Refrigerator and control method thereof

ABSTRACT

Disclosed herein is a refrigerator capable of producing carbonated water and a control method thereof. The refrigerator includes a carbonated water tank to store carbonated water a carbon dioxide gas supply valve to open/close a carbon dioxide gas flow path to guide carbon dioxide gas from a carbon dioxide gas cylinder to the carbonated water tank, and a carbonated water tank pressure sensor to detect an internal pressure of the carbonated water tank.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a refrigerator, moreparticularly a refrigerator including an apparatus for producingcarbonated water and a control method of the refrigerator.

BACKGROUND ART

A refrigerator is a home appliance including a storage chamber to storefood, and a cold air supplier to supply cold air to the storage chamberin order to keep food fresh. To satisfy consumer demand, therefrigerator may be provided with an icemaker to make ice, and adispenser to allow the user to take water or ice out of the refrigeratorfrom outside of the refrigerator without opening a door.

There are demands for providing processed beverages from therefrigerator, as well as purified water or ice, but a refrigeratortypically provides only purified water or ice to a user but processedbeverages.

DISCLOSURE Technical Problem

Therefore, it is an aspect of the present disclosure to provide arefrigerator capable of maintaining an internal pressure of a carbonatedwater tank to discharge carbonated water at a constant.

It is another aspect of the present disclosure to provide a refrigeratorcapable of informing to a user or a manager of a valve where anabnormality occurs when an abnormality occurs in any valve included in acarbonated water production module.

Technical Solution

In accordance with one aspect of the present disclosure, a refrigeratorincludes a carbonated water tank to store carbonated water, a carbonatedwater tank pressure sensor to detect an internal pressure of thecarbonated water tank, a purified water supply valve to open/close apurified water supply flow path to guide water from a purified watertank to the carbonated water tank, a carbon dioxide gas supply valve toopen/close a carbon dioxide gas supply flow path to guide carbon dioxidegas from a carbon dioxide gas cylinder to the carbonated water tank, anda controller to open the purified water supply valve and the carbondioxide gas supply valve in sequence to produce carbonated water,wherein, when an internal pressure of the carbonated water tank is lowerthan a minimum pressure after carbonated water is produced, thecontroller may open the carbon dioxide gas supply valve so that theinternal pressure of the carbonated water tank is equal to or higherthan the minimum pressure.

The refrigerator may further include a carbon dioxide gas dischargevalve to control the discharge of carbon dioxide gas in the carbonatedwater tank, wherein, when an internal pressure of the carbonated watertank is higher than a maximum pressure, the controller may open thecarbon dioxide gas discharge valve so that the internal pressure of thecarbonated water tank is equal to or lower than the maximum pressure.

While the carbonated water is produced, the controller may warn thechange of the carbon dioxide gas cylinder when the internal pressure ofcarbonated water tank is lower than a reference pressure just after thecarbon dioxide gas is supplied.

In accordance with another aspect of the present disclosure, arefrigerator includes a carbonated water tank to store carbonated water,a carbonated water tank pressure sensor to detect an internal pressureof the carbonated water tank, a purified water supply valve toopen/close a purified water supply flow path to guide water from apurified water tank to the carbonated water tank, a carbon dioxide gassupply valve to open/close a carbon dioxide gas supply flow path toguide carbon dioxide gas from a carbon dioxide gas cylinder to thecarbonated water tank, a carbon dioxide gas discharge valve to controlthe discharge of carbon dioxide gas in the carbonated water tank, and acontroller to open the carbon dioxide gas discharge valve, the purifiedwater supply valve, and the carbon dioxide gas supply valve in sequenceto produce carbonated water, wherein, while the carbonated water isproduced, the controller may display an abnormality in at least one ofthe carbon dioxide gas supply valve and the carbon dioxide gas dischargevalve based on a detection result of the carbonated water tank pressuresensor.

The controller may warn an abnormality in the carbon dioxide gasdischarge valve based on a control valve signal that is provided to thecarbon dioxide gas discharge valve and the detection result of thecarbonated water tank pressure sensor while the carbonated water isproduced.

The controller may warn an abnormality in the carbon dioxide gasdischarge valve when the internal pressure of the carbonated water tankis higher than atmospheric pressure after delivering an open valvesignal to the carbon dioxide gas discharge valve.

The controller may open the carbon dioxide gas discharge valve when theinternal pressure of the carbonated water tank is the same asatmospheric pressure after delivering an open valve signal to the carbondioxide gas discharge valve.

The controller may warn an abnormality in the carbon dioxide gas supplyvalve based on a control valve signal that is provided to the carbondioxide gas supply valve and a detection result of the carbonated watertank pressure sensor while the carbonated water is produced.

The controller may warn an abnormality in the carbon dioxide gas supplyvalve when the internal pressure of the carbonated water tank is notincreased after delivering an open valve signal to the carbon dioxidegas supply valve.

In accordance with another aspect of the present disclosure, arefrigerator includes a carbonated water tank to store carbonated water,a carbonated water tank pressure sensor to detect an internal pressureof the carbonated water tank, a carbonated water discharge valve toopen/close a carbonated water discharge flow path to guide carbonatedwater stored in the carbonated water tank to the outside of therefrigerator, and a controller to warn an abnormality in the carbonatedwater discharge valve based on a detection result of the carbonatedwater tank pressure sensor.

The controller may warn an abnormality in the carbonated water dischargevalve when the internal pressure of the carbonated water tank is notreduced after delivering an open valve signal to the carbonated waterdischarge valve.

The controller may warn an abnormality in the carbonated water dischargevalve when the internal pressure of the carbonated water tank is reducedafter delivering a close valve signal to the carbonated water dischargevalve.

In accordance with one aspect of the present disclosure, a controlmethod of a refrigerator capable of producing carbonated water includessupplying water and carbon dioxide gas sequentially to a carbonatedwater tank to produce carbonated water, detecting an internal pressureof the carbonated water tank by a carbonated water tank pressure sensorafter carbonated water is produced, and resupplying carbon dioxide gasto the carbonated water tank when the detected internal pressure of thecarbonated water tank is lower than a minimum pressure, so that theinternal pressure of the carbonated water tank is higher than areference pressure.

The control method may further include discharging carbon dioxide gasfrom the carbonated water tank when the detected internal pressure ofthe carbonated water tank is higher than the maximum pressure, so thatthe internal pressure of the carbonated water tank is lower than amaximum pressure.

The control method may further include detecting an internal pressure ofthe carbonated water tank by a carbonated water tank pressure sensorwhile carbonated water is produced and warning of the change of a carbondioxide gas cylinder when the internal pressure of the carbonated watertank is lower than the reference pressure.

In accordance with another aspect of the present disclosure, a controlmethod of a refrigerator capable of producing carbonated water includessupplying water and carbon dioxide gas sequentially to a carbonatedwater tank to produce carbonated water, detecting an internal pressureof the carbonated water tank by a carbonated water tank pressure sensorafter carbonated water is produced, and displaying an abnormality in atleast one valve of the carbon dioxide gas supply valve and the carbondioxide gas discharge valve based a detection result of the carbonatedwater tank pressure sensor.

The displaying an abnormality in at least one valve may include warningan abnormality in the carbon dioxide gas discharge valve when theinternal pressure of the carbonated water tank is higher thanatmospheric pressure after delivering an open valve signal to the carbondioxide gas discharge valve.

The displaying an abnormality in at least one valve may include warningan abnormality in the carbon dioxide gas supply valve when the internalpressure of the carbonated water tank is not increased after deliveringa close valve signal to the carbon dioxide gas discharge valve.

Advantageous Effects

In accordance with one aspect of the present disclosure, a refrigeratormay maintain an internal pressure of a carbonated water tank todischarge carbonated water at a constant by being provided with apressure sensor configured to detect an internal pressure of acarbonated water tank.

In accordance with another aspect of the present disclosure, arefrigerator may inform to a user or a manager of a valve which is notopened or not closed, by sequentially opening/closing a plurality ofvalves used for the production of carbonated water, and detecting theflow of water.

DESCRIPTION OF DRAWINGS

These and/or other aspects of the present disclosure will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a view illustrating an appearance of a refrigerator accordingto one embodiment of the present disclosure;

FIG. 2 is a view illustrating an interior of a refrigerator according toone embodiment of the present disclosure;

FIG. 3 is a view illustrating a configuration of a dispenser moduleincluded in a refrigerator according to one embodiment of the presentdisclosure;

FIG. 4 is a view illustrating a motion of a dispenser module included ina refrigerator according to one embodiment of the present disclosure;

FIG. 5 is a view illustrating a carbonated water production module and apurified water supply module included in a refrigerator according to oneembodiment of the present disclosure;

FIG. 6 is a view illustrating an assembly structure of a carbonatedwater production module included in a refrigerator according to oneembodiment of the present disclosure;

FIGS. 7A and 7B are a view illustrating an example of a flow sensorincluded in a refrigerator according to one embodiment of the presentdisclosure;

FIGS. 8A, 8B and 8C are a view illustrating an example of a carbonatedwater tank pressure sensor included in a refrigerator according to oneembodiment of the present disclosure;

FIG. 9 is a view illustrating an example of a water leakage sensorincluded in a refrigerator according to one embodiment of the presentdisclosure;

FIG. 10 is a control block diagram of a refrigerator according to oneembodiment of the present disclosure;

FIG. 11 is a view illustrating a user interface included in arefrigerator according to one embodiment of the present disclosure;

FIG. 12 is a view illustrating a method of producing carbonated water ofa refrigerator according to one embodiment of the present disclosure;

FIGS. 13 and 14 are views illustrating an example of producingcarbonated water by a refrigerator according to the method illustratedin FIG. 12;

FIG. 15 is a view illustrating a method of discharging carbonated waterof a refrigerator according to one embodiment of the present disclosure;

FIG. 16 is a view illustrating an example of discharging carbonatedwater by a refrigerator according to the method illustrated in FIG. 15;

FIG. 17 is a view illustrating a method of discharging purified water ofa refrigerator according to one embodiment of the present disclosure;

FIG. 18 is a view illustrating an example of discharging purified waterby a refrigerator according to the method illustrated in FIG. 17;

FIG. 19 is a view illustrating a method of supplying water for makingice by a refrigerator according to one embodiment of the presentdisclosure;

FIG. 20 is a view illustrating an example of supplying purified water toan ice maker in a refrigerator according to a method illustrated in FIG.19;

FIG. 21 is a view illustrating a method of determining water leakage ofa refrigerator according to one embodiment of the present disclosure;

FIGS. 22 and 23 are views illustrating an example of detecting waterleakage in a purified water supply module or a carbonated waterproduction module by a refrigerator according to a method illustrated inFIG. 21;

FIG. 24 is a view illustrating a method of determining an abnormality ina purified water supply valve by a refrigerator according to oneembodiment of the present disclosure;

FIG. 25 is a view illustrating a method of determining an abnormality ina purified water discharge valve by a refrigerator according to oneembodiment of the present disclosure;

FIG. 26 is a view illustrating a method of determining an abnormality ina carbonated water discharge valve by a refrigerator according to oneembodiment of the present disclosure;

FIG. 27 is a view illustrating a method of determining the change ofcarbon dioxide cylinder by a refrigerator according to one embodiment ofthe present disclosure;

FIG. 28 is a view illustrating a method of determining an abnormality ina carbon dioxide supply/discharge valve by a refrigerator according toone embodiment of the present disclosure;

FIG. 29 is a view illustrating a method of determining an abnormality ina carbon dioxide discharge valve by a refrigerator according to oneembodiment of the present disclosure;

FIG. 30 is a view illustrating a method of supplementing carbon dioxidegas of a refrigerator according to one embodiment of the presentdisclosure;

FIG. 31 is a view illustrating a method of discharging carbon dioxidegas of a refrigerator according to one embodiment of the presentdisclosure;

FIG. 32 is a view illustrating a carbonated water production module anda purified water supply module of a refrigerator according to anotherembodiment of the present disclosure;

FIG. 33 is a view illustrating a method of discharging carbonated waterof a refrigerator according to another embodiment of the presentdisclosure;

FIG. 34 is a view illustrating an example of discharging carbonatedwater by a refrigerator according to the method illustrated in FIG. 33;

FIG. 35 is a view illustrating a method of determining an abnormality ina carbonated water discharge valve by a refrigerator according toanother embodiment of the present disclosure;

FIG. 36 is a view illustrating a carbonated water production module anda purified water supply module of a refrigerator according to anotherembodiment of the present disclosure;

FIG. 37 is a view illustrating a method of producing carbonated water ofa refrigerator according to another embodiment of the presentdisclosure;

FIG. 38 is a view illustrating an example of a method of determining anabnormality in a water level sensor by a refrigerator according toanother embodiment of the present disclosure; and

FIG. 39 is a view illustrating another example of a method ofdetermining an abnormality in a water level sensor by a refrigeratoraccording to another embodiment of the present disclosure.

BEST MODE

Reference will now be made in detail to embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout.

FIG. 1 is a view illustrating an appearance of a refrigerator accordingto one embodiment of the present disclosure, and FIG. 2 is a viewillustrating an interior of a refrigerator according to one embodimentof the present disclosure.

Referring to FIGS. 1 to 2, a refrigerator 1 according to one embodimentof the present disclosure may include a body 10, a storage chamber 20and 30 provided inside the body 10, and a cold air supplier (not shown)to supply cool air to the storage chamber 20 and 30.

The body 10 may include an inner case to form the storage chamber 20 and30, an outer case coupled to the inner case at an outside of the innercase to form the appearance of the refrigerator 1, and an insulatordisposed between the inner and outer cases, to insulate the storagechamber 20 and 30.

The storage chamber 20 and 30 may be divided into an upper refrigeratingcompartment 20 and a lower freezing compartment 30 by an intermediatepartition 11. The refrigerating compartment 20 may be kept at atemperature of approximately 3° C., to store food in a refrigeratedstate, whereas the freezing compartment 30 may be kept at a temperatureof approximately −18.5° C., to store food in a frozen state.

Hereinbefore the refrigerating compartment 20 and the freezingcompartment 30 which are divided into upside and down are illustrated,but are not limited thereto. Thus the refrigerating compartment 20 andthe freezing compartment 30 may be divided into side by side by theintermediate partition 11.

Racks 23 may be provided at the refrigerating compartment 20, to placefood thereon. In the refrigerating compartment 20, at least one storagebox 27 may also be provided to store food in a closed state.

In addition, a purified water supply module 70 configured to purifywater and store purified water may be provided in the refrigeratingcompartment 20, and the purified water supply module 70 may include apurification filter 73 to purify water supplied from water source and apurified water tank 71 to store purified water.

As illustrated in FIG. 2, the purified water supply module 70 may bebetween a plurality of storage boxes 27, but is not limited thereto. Itmay be enough for the purified water supply module 70 to be disposedinside the refrigerating compartment 20 so that water in the purifiedwater supply module 70 is cooled by cool air from the inside of therefrigerating compartment 20.

A detailed configuration of the purified water supply module 70 will bedescribed later with reference to FIGS. 5 and 6.

In addition, an ice making compartment 80 to produce ice may be providedat an upper corner of the refrigerating compartment 20 to be separatedfrom the refrigerating compartment 20. In the ice making compartment 80,an icemaker 81 to make and store ice may be provided. The icemaker 81may include an ice making tray to produce ice by using water suppliedfrom the purified water tank 70, and an ice bucket to store ice producedin the ice making tray.

Each of the refrigerating compartment 20 and the freezing compartment 30has an open front side to allow food to be place therein or withdrawtherefrom. The open front side of the refrigerating compartment 20 maybe opened/closed by a pair of rotatable doors 21 and 22 hinge-coupled tothe body 10. The open front side of the freezing compartment 30 may beopened/closed by a sliding door 31 slidable with respect to the body 10.

Door guards 24 may be provided at rear surfaces of the refrigeratingcompartment doors 21 and 22 to store food. A gasket 28 may be providedalong an edge of the rear surface of the refrigerating compartment door21 and 22 to confine cold air in the refrigerating compartment 20 byclosing between the refrigerating compartment door 21 and 22 and thebody 10 when the refrigerating compartment door 21 and 22 are closed.

A rotating bar 26 may be selectively provided at any one of therefrigerating compartment doors 21 and 22, to confine cold air in therefrigerating compartment 20 by closing between the refrigeratingcompartment door 21 and 22 when the refrigerating compartment door 21and 22 are closed.

In addition, at any one of the refrigerating compartment doors 21 and22, a dispenser module 90 may be provided to allow the user to put outpurified water, carbonated water or ice from the outside of therefrigerator 1 without opening the refrigerating compartment door 21,and a user interface 300 may be provide to receive an input of a controlcommand related to operations of the refrigerator 1, and to displayoperation information of the refrigerator 1.

The dispenser module 90 may include a dispensation space 91 in which acontainer such as a cup, is inserted to dispense water or ice, adispenser lever 93 to operate the dispenser module 90 to dischargepurified water, carbonated water or ice, and a dispenser nozzle 95 inwhich purified water or carbonated water is discharged.

A detailed configuration and operation of the dispenser module 90 willbe described later with reference to FIGS. 3 and 4.

The user interface 300 may include a touch switch to receive an input ofa variety of control commands of the refrigerator 1 from a user, and adisplay unit to display operation information of the refrigerator 1 tothe user.

The user interface 300 may receive a target temperature of therefrigerating compartment 20, a target temperature of the freezingcompartment 30, whether to activate the carbonated water production, aconcentration of carbonated water, and the likes, and may display apresent temperature of the refrigerating compartment 20, a presenttemperature of the freezing compartment 30, whether to producecarbonated water, a concentration of produced carbonated water, and thelikes corresponding to a control command of a user.

A detailed configuration and operation of the user interface 300 will bedescribed later with reference to FIGS. 10 and 11.

On the rear surface of the refrigerating compartment door 21 where thedispenser module 90 is provided, a carbonated water production module100 to produce and store carbonated water may be mounted.

The carbonated water production module 100 will be described withreference to FIGS. 5 and 6.

FIG. 3 is a view illustrating a configuration of a dispenser moduleincluded in a refrigerator according to one embodiment of the presentdisclosure and FIG. 4 is a view illustrating a motion of a dispensermodule included in one refrigerator according to one embodiment of thepresent disclosure.

Referring to FIGS. 3 and 4, a dispenser lever 93 may include a firstdispenser lever 93 a, a second dispenser lever 93 b, and a thirddispenser lever 93 c.

The first lever 93 a may be formed to be extended from an upper side toan lower side, and may be rotatably movable back and forth with respectto a first shaft (not shown) provided on an upper side of the firstlever 93 a.

Particularly, the first lever 93 a may be rotatably moved between afirst position P1 and a second position P2 with respect to the firstshaft (not shown). For example, when the user presses the first lever 93a backward, the first lever 93 a may be moved from the first position P1to the second position P2, and when the user releases the first lever 93a, the first lever 93 a may automatically return to the first positionP1.

The second lever 93 b may be provided to be overlapped in the front ofthe first lever 93 a, and may be rotatably movable back and forth withrespect to a second shaft (not shown) provided on an upper side of thesecond lever 93 b.

The second lever 93 b may be rotatably moved between a third position P3and a fourth position P4 with respect to the second shaft (not shown).For example, when the user presses the second lever 93 b backward, thesecond lever 93 b may be moved from the third position P3 to the fourthposition P4, and when the user releases the second lever 93 b, thesecond lever 93 b may automatically return to the third position P3.

The third lever 93 c may be protruded toward the front of the dispenser90, and may be rotatably moved up and down with respect to a third shaft93 c-1 provided on a rear side of the third lever 93 c.

Particularly, the third lever 93 c may be rotatably moved between afifth position P5 and a sixth position P6 with respect to the thirdshaft (93 c-1). For example, when the user presses the third lever 93 cdownward, the third lever 93 c may be moved from the fifth position P5to the sixth position P6 and fixed at the sixth position P6. Inaddition, when the user presses the third lever 93 c upward, the thirdlever 93 c may be moved from the sixth position P6 to the fifth positionP5 and fixed at the fifth position P5.

The user may input commands of discharging ice, purified water, orcarbonated water by manipulating the first lever 93 a, the second lever93 b, or the third lever 93 c according to a predetermined operationmethod.

For example, when the user presses the first dispenser lever 93 a, therefrigerator 1 may discharge purified water. That is, when the firstdispenser lever 93 a is placed in the second position P2, therefrigerator 1 may discharge purified water via the dispenser module 90,and when the first dispenser lever 93 a is placed in the first positionP1, the refrigerator 1 may stop discharging purified water.

For another example, when the user places the third dispenser lever 93 cat the fifth position P5, and presses the second dispenser lever 93 b,the refrigerator 1 may discharge carbonated water. When the user placesthe third dispenser lever 93 c at the sixth position P6, and presses thesecond dispenser lever 93 b, the refrigerator 1 may discharge ice. Inother words, the refrigerator 1 may discharge carbonated water or icedepending on the position of the third dispenser lever 93 c when thesecond dispenser lever 93 b is placed in the fourth position P4, and maystop discharging carbonated water or ice when the second dispenser lever93 b is placed in the third position P3.

Hereinbefore the configuration of the refrigerator 1 according to oneembodiment of the present disclosure is described. However, thedescription of the refrigerator 1 may be an example of embodiments, andthus the present disclosure may apply to a refrigerator having anystructure capable of producing carbonated water.

Hereinafter a carbonated water production module 100 provided in arefrigerator 1 will be described.

FIG. 5 is a view illustrating a carbonated water production module and apurified water supply module included in a refrigerator according to oneembodiment of the present disclosure, and FIG. 6 is a view illustratingan assembly structure of a carbonated water production module includedin a refrigerator according to one embodiment of the present disclosure.

FIGS. 7A and 7B are a view illustrating an example of a flow sensorincluded in a refrigerator according to one embodiment of the presentdisclosure, FIGS. 8A, 8B and 8C are a view illustrating an example of acarbonated water tank pressure sensor included in a refrigeratoraccording to one embodiment of the present disclosure, and FIG. 9 is aview illustrating an example of a water leakage sensor included in arefrigerator according to one embodiment of the present disclosure.

An example of the purified water supply module 70 and the carbonatedwater production module 100 will be described with reference to FIGS. 5to 9

The purified water supply module 70 may supply purified water, which isdischarged via the dispenser module 90 or used for producing carbonatedwater.

As illustrated in FIG. 5, the purified water supply module 70 mayinclude a purified water tank 71 to store purified water, a purificationfilter 73 to purify water supplied from the water source 40, a flow pathswitching valve 75 to distribute purified water into the ice maker 81 orthe purified water tank 71, and a flow sensor 77 to detect an amount ofwater supplied to the ice maker 81 or the purified water tank 71.

As mentioned above, the purified water tank 71 may be provided in theplurality of storage boxes 27 (refer to FIG. 2), and the purificationfilter 73 may be provided to be adjacent to the center of the purifiedwater tank 71.

The flow path switching valve 75 may be implemented by a three-way valveincluding an inlet 75 a connected to the purification filter 73, a firstoutlet 75 b connected to the ice maker 81 and a second outlet 75 cconnected to the purified water tank 71, as illustrated in FIG. 5.

The flow path switching valve 75 may supply purified water supplied fromthe purification filter 73 to any one of the purified water tank 71 andthe ice maker 81.

Particularly, when an operation of making ice is not required, the flowpath switching valve 75 may open a flow path on the side of the purifiedwater tank 71 and close a flow path on the side of the ice maker 81 tosupply purified water to the purified water tank 71.

In addition, when an operation of making ice is required, the flow pathswitching valve 75 may close a flow path on the side of the purifiedwater tank 71 and open a flow path on the side of the ice maker 81 tosupply purified water to the ice maker 81.

As illustrated in FIGS. 7A and 7B, the flow sensor 77 may include a flowsensor body 77 a in the shape of a cylinder, and a rotor 77 b insertedinto the inside of the flow sensor body 77 a.

The rotor 77 b may be rotated by a flow of water supplied from the watersource 40, and may include a holder 77 c to fix the rotator 77 b to theinside of the flow sensor body 77 a, an impeller 77 d rotated withrespect to a rotation shaft 77 e according to the flow water, and apermanent magnet 77 f rotated together with the impeller 77 d.

In the outside of the flow sensor body 77 a, a hall sensor 77 g todetect a magnetic field generated by the permanent magnet 77 f of therotor 77 b may be provided.

According to the rotation of the permanent magnet 77 f, the magneticfield may be detected at the same period as a period of rotation of therotor 77 b by the hall sensor 77 g, and whenever the magnetic field isdetected, electric pulses may be outputted.

Based on the total number of electric pulses outputted by the flowsensor 77, the refrigerator 1 may estimate an amount of water suppliedto the purified water supply module 70 from the external water source40, and may estimate flow velocity of water supplied to the purifiedwater supply module 70 based on the number of electric pulses per unittime i.e., 1 second.

In FIG. 5, the flow sensor 77 is disposed between the external watersource 40 and the purification filter 73, but is not limited thereto.The flow sensor 77 may be disposed between the purification filter 73and the flow path switching valve 75.

The carbonated water production module 100 may produce and storecarbonated water inside the refrigerator 1.

The carbonated water production module 100 may include a carbonatedwater tank 110 to produce carbonated water by mixing of purified waterwith carbon dioxide gas and to store the carbonated water, a carbondioxide gas cylinder 120 to store carbon dioxide gas, a valve assembly130 to control a flow of purified water and carbonated water. Thecarbonated water production module 100 may further include a variety ofvalves 150, 160, 170, 180, and 190 to connect between the carbonatedwater tank 110, the carbon dioxide cylinder 120 and the valve assembly130, and a module case 140 where the carbonated water tank 110, thecarbon dioxide gas cylinder 120 and the valve assembly 130 are placed.

The carbonated water tank 110 may produce carbonated water by mixing ofpurified water supplied from the purified water tank 70 with carbondioxide gas supplied from the carbon dioxide gas cylinder 120, and maystore the produced carbonated water. In addition, as illustrated in FIG.6, the carbonated water tank 110 may be placed in a first upperaccommodation space 141 a of the module case 140.

The carbonated water tank 110 may be formed to have a predetermined sizeto store approximately 1 l of purified water. The carbonated water tank110 may be made of a stainless steel material in order to minimize thesize of the carbonated water tank 110 while sustaining a high pressureand exhibiting corrosion resistance.

In the carbonated water tank 110, a carbonated water tank pressuresensor 112 to detect the internal pressure of the carbonated water tank110, a carbon dioxide gas discharge valve 113 to discharge carbondioxide gas inside the carbonated water tank 110, and a safety valve 114to discharge carbon dioxide gas inside the carbonated water tank 110,when the internal pressure of the carbonated water tank 110 is higherthan the reference pressure, may be provided.

The carbonated water tank pressure sensor 112 may detect the internalpressure of the carbonated water tank 110 and output an electricalsignal corresponding to the detected pressure.

As illustrated in FIGS. 8A, 8B and 8C, the carbonated water tankpressure sensor 112 may have various shapes. For example, the carbonatedwater tank pressure sensor 112 may employ a strain gauge pressure sensor112 a, a capacitive pressure sensor 112 b, a piezoelectric pressuresensor 112 c and the likes.

As illustrated in FIG. 8A, the strain gauge pressure sensor 112 a mayinclude a sensor body 112 a-1, a diaphragm 112 a-2 having a shape, whichis variable according to the internal pressure of the carbonated watertank 110, a strain gauge 112 a-3 mounted to the diaphragm 112 a-2. Theshape of the strain gauge 112 a-3 may be variable together with thediaphragm 112 a-2 according to the internal pressure of the carbonatedwater tank 110, and an electrical resistance may be variable accordingto the variation of the shape.

The strain gauge pressure sensor 112 a may detect carbon dioxide gaspressure of the inside of the carbonated water tank 110 by using theelectrical resistance of the strain gauge 112 a-3 variable according tothe internal pressure of the carbonated water tank 110.

As illustrated in FIG. 8B, the capacitive pressure sensor 112 b mayinclude a sensor body 112 b-1, a diaphragm 112 b-2 having a shapevariable according to the internal pressure of the carbonated water tank110, a fixation electrode 112 b-3 installed to be separated from thediaphragm 112 b-2. The capacitance between the diaphragm 112 b-2 and thefixation electrode 112 b-3 may be variable according to the internalpressure of the carbonated water tank 110.

The capacitive pressure sensor 112 b may detect carbon dioxide gaspressure of the inside of the carbonated water tank 110 by using thecapacitance between the diaphragm 112 b-2 and the fixation electrode 112b-3 variable according to the internal pressure of the carbonated watertank 110.

As illustrated in FIG. 8C, the piezoelectric pressure sensor 112 c mayinclude a sensor body 112 c-1, and a piezoelement 112 c-2 variableaccording to the internal pressure of the carbonated water tank 110. Thepiezoelement 112 c-2 may output variable voltage according to thevariation of the shape.

The piezoelectric pressure sensor 112 c may detect carbon dioxide gaspressure of the inside of the carbonated water tank 110 by using theoutput voltage of the piezoelement 112 c-2 variable according to theinternal pressure of the carbonated water tank 110.

The carbon dioxide gas cylinder 120 may store carbon dioxide gas at ahigh pressure of approximately 45 to 60 bars, and may be mounted to acylinder connector 145 of the module case 140. In addition, the carbondioxide gas cylinder 120 may be placed in the lower accommodation space141 c of the module case 140.

Carbon dioxide gas in the carbon dioxide gas cylinder 120 may besupplied to the carbonated water tank 110 via a carbon dioxide gassupply flow path 150 to connect the carbon dioxide gas cylinder 120 tothe carbonated water tank 110.

The carbon dioxide gas supply flow path 150 may guide carbon dioxide gasstored in the carbon dioxide gas cylinder 120 to the carbonated watertank 100. A carbon dioxide gas regulator 151 to adjust the pressure ofcarbon dioxide gas, a carbon dioxide gas pressure sensor 154 to detect apressure of discharged carbon dioxide gas, a carbon dioxide gas supplyvalve 152 to open/close the carbon dioxide gas supply flow path 150, anda carbon dioxide gas backflow prevention valve 153 to prevent backflowof carbon dioxide gas may be provided on the carbon dioxide gas supplyflow path 150.

The carbon dioxide gas regulator 151 may be provided on a carbon dioxidegas outlet of the carbon dioxide gas cylinder 120 and may adjust thepressure of carbon dioxide gas discharged from the carbon dioxide gascylinder 120. Particularly, the carbon dioxide gas regulator 151 mayreduce the pressure of carbon dioxide gas, which is supplied to thecarbonated water tank 110, to approximately 8.5 bar.

The carbon dioxide gas pressure sensor 154 may be provided on a carbondioxide gas outlet of the carbon dioxide regulator 151 and may detectthe pressure of carbon dioxide gas, which is reduced by the carbondioxide gas regulator 151.

The carbon dioxide gas pressure sensor 154 may employ a pressure switchto output a low pressure sensing signal corresponding to the reducedpressure of carbon dioxide gas when the pressure of carbon dioxide gasreduced by the carbon dioxide gas regulator 151 is reduced below apredetermined pressure,

The valve assembly 130 may be placed in the second upper accommodationspace 141 b of the module case 140, and may include a purified watersupply valve 131 to regulate to supply purified water to the carbonatedwater tank 110, a purified water discharge valve 133 to regulate thedischarge of purified water and a carbonated water discharge valve 135to regulate the discharge of carbonated water.

The purified water supply valve 131 may allow purified water to besupplied to the carbonated water tank 110, or may stop supplyingpurified water. Particularly, when the purified water supply valve 131is opened, purified water may be supplied to the carbonated water tank110 from the purified water supply module 70, and when the purifiedwater supply valve 131 is closed, purified water may be not supplied tothe carbonated water tank 110.

One end of the purified water supply valve 131 may be connected to afirst purified water supply flow path 160 to guide purified water fromthe purified water supply module 70 to the valve assembly 130, and theother end of the purified water supply valve 131 may be connected to asecond purified water supply flow path 170 to guide purified waterpassed through the purified water supply valve 131 to the carbonatedwater tank 110.

The purified water discharge valve 133 may allow the discharge of thepurified water via the dispenser module 90 or may stop the discharge ofthe purified water. Particularly, when the purified water dischargevalve 133 is opened, purified water may be discharged from the purifiedwater supply module 70 via the dispenser module 90, and when thepurified water discharge valve 133 is closed, purified water may be notdischarged.

One end of the purified water discharge valve 133 may be connected tothe first purified water supply flow path 160 to guide purified waterfrom the purified water supply module 70 to the valve assembly 130, andthe other end of the purified water supply valve 131 may be connected toan integrated discharge flow path 190 to guide purified water orcarbonated water to the dispenser module 90.

The carbonated water discharge valve 135 may allow the discharge of thecarbonated water via the dispenser module 90 or may stop the dischargeof the carbonated water. Particularly, when the carbonated waterdischarge valve 135 is opened, carbonated water may be discharged fromthe carbonated water tank 110 via the dispenser module 90, and when thecarbonated water discharge valve 135 is closed, carbonated water may benot discharged.

One end of the carbonated water discharge valve 135 may be connected toa carbonated water discharge flow path 180 to guide carbonated waterfrom the carbonated water tank 110 to the valve assembly 130, and theother end of the carbonated water discharge valve 135 may be connectedto the integrated discharge flow path 190 to guide purified water orcarbonated water to the dispenser module 90.

The purified water supply valve 131, the purified water discharge valve133 and the carbonated water discharge valve 135 may be independentlyopenable or closeable, and may be configured with a solenoid valve.

As mentioned above, the valve assembly 130 may include the threeindependent valves 131, 133, and 135, and may further include one threeway flow path switch valve to selectively supply purified water from thepurified water supply module 70 to the carbonated water tank 110 or thedispenser module 90, and another three-way flow path switch valve tosupply purified water from the purified water supply module 70 to thedispenser module 90 or to supply carbonated water from the carbonatedwater tank 110 to the dispenser module 90.

The first purified water supply flow path 160 may connect the purifiedwater supply module 70 to the valve assembly 130, and may guide purifiedwater in the purified water supply module 70 from the purified watersupply module 70 to the valve assembly 130.

One end of the first purified water supply valve 160 may be connected tothe purified water supply module 70, and the other end of the firstpurified water supply valve 160 may be connected to the purified watersupply valve 131 and the purified water discharge valve 133 of the valveassembly 130. In addition, purified water supplied via the firstpurified water supply valve 160 may be supplied to the carbonated watertank 100 or may be discharged via the dispenser module 90 depending onthe open/close of the purified water supply valve 131 and the purifiedwater discharge valve 133

The second purified water supply flow path 170 may connect thecarbonated water tank 110 to the valve assembly 130, and may guidepurified water passed through the valve assembly 130 to the carbonatedwater tank 110.

One end of the second purified water supply flow path 170 may beconnected to the purified water supply valve 131 of the valve assembly130 and the other end of the second purified water supply flow path 170may be connected to the carbonated water tank 110.

The carbonated water discharge flow path 180 may connect the carbonatedwater tank 110 to the valve assembly 130, and may guide carbonated waterof the carbonated water tank 110 to the valve assembly 130.

One end of the carbonated water discharge flow path 180 may be connectedto the carbonated water tank 110 and the other end of the carbonatedwater discharge flow path 180 may be connected to the carbonated waterdischarge valve 135 of the valve assembly 130. In addition, carbonatedwater supplied via the carbonated water discharge flow path 180 may bedischarged via the dispenser module 90 depending on the open/close ofthe carbonated water discharge valve 135.

On the carbonated water discharge flow path 180, a carbonated waterregulator 181 to adjust the pressure of the carbonated water may bedisposed. The carbonated water regulator 181 may reduce the pressure ofthe carbonated water discharged from the carbonated water tank 110 belowat a certain pressure so that a certain amount of the carbonated watermay be discharged via the dispenser module 90.

The integrated discharge flow path 190 may be integrally formed by apurified water discharge flow path 190 a to discharge purified water anda carbonated water discharge flow path 190 b to discharge carbonatedwater, and may guide carbonated water and purified water passed throughthe valve assembly 130 to the dispenser module 90.

The purified water discharge flow path 190 a of the integrated dischargeflow path 190 may be connected to the purified water discharge valve 133of the valve assembly 130, and the carbonated water discharge flow path190 b of the integrated discharge flow path 190 may be connected to thecarbonated water discharge valve 135 of the valve assembly 130.

On the integrated discharge flow path 190, a residual water dischargeprevention valve 191 to open/close the integrated discharge flow path190 may be provided so that remaining purified water or remainingcarbonated water in the integrated discharge flow path 190 may be notdischarged to the outside via the dispenser module 90 in a state wherethe purified water discharge valve 133 and the carbonated waterdischarge valve 135 are closed.

The residual water discharge prevention valve 191 may be disposed on anend portion of the integrated discharge flow path 190.

The integrated discharge flow path 190, which is integrally formed bythe purified water discharge flow path 190 a and the carbonated waterdischarge flow path 190 b, is described, but is not limited thereto. Thepurified water discharge flow path 190 a and the carbonated waterdischarge flow path 190 b may be separately provided.

The module case 140 may include a back case 141 having an opened side,and a cover 143 coupled to the open side of the back case 141.

In a state where the cover 143 is coupled to the back case 141, thecarbon dioxide gas cylinder 120, the carbonated water tank 110, and thevalve assembly 130, all of which are placed in the module case 140, maybe not exposed to the outside.

The cover 143 may be divided into a first cover 143 a to open/close theupper accommodation spaces 141 a and 141 b, in which the carbonatedwater tank 110 and the valve assembly 130 are placed, respectively, anda second cover 143 b to open/close the lower accommodation space 141 c,in which the carbon dioxide gas cylinder 120 is placed. The first cover143 a and second cover 143 b may be independently opened or closed.

Therefore, when the carbon dioxide gas cylinder 120 is replaced with anew one due to exhaustion of carbon dioxide gas thereof, the replacementmay be achieved by separating only the second cover 143 b withoutopening the first cover 143 a. Thus, it may be possible to prevent coldair in the upper accommodation space 141 a from being outwardlydischarged during the replacement of the carbon dioxide gas cylinder 120because the first cover 143 a is maintained in a closed state.

In addition, a water leakage sensor 147 may be disposed on a bottomsurface of the upper accommodation space 141 a and 141 b where thecarbonated water tank 110 and the valve assembly 130 are placed.

When water leakage occurs in the carbonated water tank 110 or the valveassembly 130, leaked water may be remained in the bottom surface of theupper accommodation space 141 a and 141 b, and thus the water leakagesensor 147 may determine whether water leakage occurs or not bydetecting remaining water on the bottom surface of the upperaccommodation space 141 a and 141 b.

The water leakage sensor 147 may include a pair of electrode, and maydetermine that water leakage occurs when the current flows on a pair ofelectrode, or may determine that water leakage does not occur when thecurrent does not flow on a pair of electrode.

The water leakage sensor 147 may be an optional component, and thus maybe not an essential component for the operation of a refrigerator 1.

FIG. 10 is a control block diagram of a refrigerator according to oneembodiment of the present disclosure, and FIG. 11 is a view illustratinga user interface included in a refrigerator according to one embodimentof the present disclosure.

Referring to FIGS. 10 and 11, a refrigerator 1 may include a userinterface 300 to interact with a user along with the above-describedcool air supplier (not shown), the flow sensor 77 included in thepurified water supply module 70, a variety of sensors 154, 111, 112, and147, and a variety of valves 152, 113, 131, 133, 135, and 191 includedin the carbonated water production module 100, a storage 400 to storeprograms and data related to an operation of the refrigerator 1, and acontroller 500 to control the operation of the refrigerator 1.

The user interface 300 may include a carbonated water producingactivation unit 310 to receive an input of a command of producingcarbonated water from the user and to display information related toproducing carbonated water, a carbonated water concentration settingunit 320 to receive an input of a command of setting a concentration ofcarbonated water from the user and to display information related tosetting a concentration of carbonated water, a carbonated waterhigh-speed producing unit 330 to receive an input of producingcarbonated water at high-speed from the user and to display informationrelated to producing carbonated water at high-speed, and a carbonatedwater level displaying unit 340 to display a carbonated water level.

Each unit 310, 320, 330, 340 provided in the user interface 300 mayinclude a touch switch to detect a touch or a pressure of the user and adisplay unit to display images to the user.

The touch switch may employ a push switch, a membrane switch to detect apressure of the user or a touch pad to detect a touch of the user. Inaddition, the display unit may employ Liquid Crystal Display (LCD),Light Emitting Diode (LED), or Organic Light Emitting Diode (OLED).

Each unit 310, 320, 330, 340 provided in the user interface 300 mayemploy a touch screen. The touch screen may be integrally formed withthe touch switch and the display unit, and may receive an input of acontrol command through a touch of the user and to display informationof operation corresponding to a control command.

The carbonated water producing activation unit 310 may receive an inputof a command of activating carbonated water production from the user. Inaddition, the carbonated water producing activation unit 310 may includea carbon dioxide gas low-pressure display unit 311 to warn that apressure of carbon dioxide gas discharged from the carbon dioxide gascylinder 120 is less than a predetermined pressure, and a carbonatedwater producing display unit 313 to display producing carbonated waterat real time.

For example, when a pressure of carbon dioxide gas discharged from thecarbon dioxide gas cylinder 120 is less than the predetermined pressure,the refrigerator 1 may warn low-pressure of carbon dioxide gas bydisplaying a carbon dioxide gas low-pressure image on the carbon dioxidegas low-pressure display unit 311. In addition, when producingcarbonated water, the refrigerator 1 may display carbonated waterproduction to the user by displaying a carbonated water producing imageon the carbonated water producing display unit 313.

When the user touches or presses the carbonated water producingactivation unit 310, the refrigerator 1 may start to produce carbonatedwater and may display the carbonated water producing image on thecarbonated water producing display unit 313.

The carbonated water concentration setting unit 320 may receive an inputof a command of setting a concentration of carbonated water from theuser. The carbonated water concentration setting unit 320 may include apresent concentration display unit 321 to display a concentration ofcarbonated water currently stored in the carbonated water tank 110 and atarget concentration display unit 323 to display a set concentration ofcarbonated water which is set by the user.

For example, as illustrated in FIG. 11, the present concentrationdisplay unit 321 may display a present concentration of carbonated waterstored in the carbonated water tank 110 in 7-segment displays, and thetarget concentration display unit 323 may display an image correspondingto a target concentration of carbonated water inputted by the user.

When the user touches or presses the carbonated water concentrationsetting unit 320, the refrigerator 1 may change a target concentrationof carbonated water and a target concentration of carbonated waterdisplayed on the target concentration display unit 323.

The carbonated water high-speed producing unit 330 may receive an inputof a command of producing a carbonated water at high-speed from the userand may display an operation of a carbonated water high-speed productionaccording to the command of producing a carbonated water at high-speed.

For example, when the user touches or presses the carbonated waterhigh-speed producing unit 330, the refrigerator 1 may produce carbonatedwater at high-speed according to a predetermined method, and may displaya producing carbonated water at high-speed image on the carbonated waterhigh-speed producing unit 330.

The carbonated water level displaying unit 340 may display a water levelof remaining carbonated water stored in the carbonated water tank 110.

For example, the refrigerator 1 may classify the water level ofcarbonated water stored in the carbonated water tank 110 by three levelsbetween the highest level and the lowest level. The carbonated waterlevel displaying unit 340 may display a carbonated water leveldisplaying image according to the water level of carbonated water.

The storage 400 may store programs and data related to cooling operationof the refrigerator 1 and programs and data related to carbonated waterproduction.

For example, the storage 400 may store a target temperature of therefrigerating compartment 20, a target temperature of the freezingcompartment 30, etc. related to the cooling operation, and a carbonatedwater level, a present concentration of carbonated water, a targetconcentration of carbonated water, etc. related to carbonated waterproduction.

The storage 400 may employ nonvolatile memory, such as, magnetic disc,solid state disk, etc. to store permanently programs and data to controlthe operation of the refrigerator 1.

The controller 500 may control overall operation of the refrigerator 1.

Particularly, the controller 500 may control the carbonated waterproduction module 100 to produce carbonated water according to a targetconcentration, a carbonated water level, wherein the carbonated water isstored in the carbonated water tank 110, and to discharge carbonatedwater via the dispenser module 90 according to a command of dischargingcarbonated water.

The controller 500 may include a memory 520 to memory control programsand data read from the storage 400, and a microprocessor 510 to performcalculation according to control programs and data stored in the memory520.

The memory 520 may include volatile memory, such as, D-RAM, S-RAM, butis not limited thereto. The memory 520 may include nonvolatile memory,such as, flash memory, and erasable programmable read only memory(EPROM).

The microprocessor 510 may perform calculation to control a variety ofcomponents included in the refrigerator 1 according to control programsand data stored in the memory 520

Particularly, the microprocessor 510 may process the detection result ofthe carbon dioxide gas pressure sensor 154, the carbonated water tankpressure sensor 112, and the flow sensor 77, and may perform calculationto control the carbon dioxide gas supply valve 152, the carbon dioxidegas discharge valve 113, the purified water supply valve 131, thepurified water discharge valve 133, the carbonated water discharge valve135 and the residual water discharge prevention valve 191.

Operations of a refrigerator 1 described in the following may bedescribed as operations by control operations of the controller 500.

Hereinbefore the configuration of the refrigerator 1 is described.

Hereinafter the operation of the refrigerator 1, particularly producingcarbonated water and discharging carbonated water, according to oneembodiment of the present disclosure will be described.

FIG. 12 is a view illustrating a method of producing carbonated water ofa refrigerator according to one embodiment of the present disclosure andFIGS. 13 and 14 are views illustrating an example of producingcarbonated water by a refrigerator according to the method illustratedin FIG. 12.

A method of producing carbonated water 1000 of a refrigerator 1 will bedescribed with reference to FIGS. 12 to 14.

At first, the refrigerator 1 may determine whether conditions forstarting to produce carbonated water are satisfied (operation 1010). Theterm of “conditions for starting to produce carbonated water” mayrepresent conditions to allow the refrigerator 1 to start to producecarbonated water.

For example, when a carbonated water level of carbonated water stored inthe carbonated water tank 110 is lower than the lowest level, therefrigerator 1 may automatically start to produce carbonated water. Inaddition, when the user inputs a command of carbonated water productionactivation through the user interface 300, the refrigerator 1 may startto produce carbonated water.

The refrigerator 1 may display carbonated water production on the userinterface 300 (operation 1020). For example, the refrigerator 1 maydisplay a carbonated water production image on the carbonated waterproducing display unit 313 provided in the carbonated water producingactivation unit 310.

The refrigerator 1 may supply purified water to the carbonated watertank 110 (operation 1030).

The refrigerator 1 may open the purified water supply valve 131 tosupply purified water to the carbonated water tank 110.

At this time, the refrigerator 1 may open the carbon dioxide gasdischarge valve 152 to smoothly supply purified water to the carbonatedwater tank 110. Therefore, it may prevent a condition where purifiedwater is not smoothly supplied to the carbonated water tank 110 when aninternal pressure of the carbonated water tank 110 is higher than asupply pressure of purified water due to carbon dioxide gas in thecarbonated water tank 110.

When the purified water supply valve 131 is opened, as illustrated inFIG. 13, purified water may be supplied from the water tank 71 to thecarbonated water tank 110 along the purified water supply flow path 160,and the purified water supply flow path 170. In addition, water, whichis the same amount as water supplied to the carbonated water tank 110,may be supplied to the purified water tank 71 from the outside watersource 40 after passed through the flow sensor 77, the purificationfilter 73 and the flow path switching valve 75.

The refrigerator 1 may determine whether the amount of water stored inthe carbonated water tank 110 is larger than the capacity of thecarbonated water tank 110 (operation 1040).

The refrigerator 1 may estimate the amount of purified water supplied tothe carbonated water tank 100 by using the flow sensor 77, and mayestimate the amount of purified water stored in the carbonated watertank 110 by accumulating the amount of purified water supplied to thecarbonated water tank 110.

Purified water may be supplied to the carbonated water tank 110 by thewater pressure of the outside water source 40, and thus the amount ofthe purified water supplied to the carbonated water tank 110 may be thesame as the amount of purified water supplied to the purified watersupply module 70 from the outside water source 40. In addition, therefrigerator 1 may estimate the amount of purified water supplied to thepurified water supply module 70 from the outside water source 40 byusing the flow sensor 77.

As mentioned above, the refrigerator 1 may estimate the amount ofpurified water supplied to the carbonated water tank 110 by using theflow sensor 77.

The refrigerator 1 may estimate the amount of purified water stored inthe carbonated water tank 110 by accumulating the amount of suppliedpurified water.

For example, when the refrigerator 1 produces carbonated water since allof carbonated water of the carbonated water tank 110 is finished, therefrigerator 1 may estimate the amount of purified water stored in thecarbonated water tank 110 by accumulating the amount of suppliedpurified water by using the flow sensor 77.

For, another example, when the refrigerator 1 produces carbonated waterby a command of producing carbonated water from a user, the refrigerator1 estimate the amount of purified water stored in the carbonated watertank 110 by accumulating the amount of supplied purified water by usingthe flow sensor 77 in the remaining carbonated water in the carbonatedwater tank 110.

When the amount of stored purified water is not larger than the capacityof the carbonated water tank 110 (NO of operation 1040), therefrigerator 1 may continue to supply purified water to the carbonatedwater tank 110.

When the amount of stored purified water is larger than the capacity ofthe carbonated water tank 110 (YES of operation 1040), the refrigerator1 may stop supplying purified water to the carbonated water tank 110,and may supply carbon dioxide gas to the carbonated water tank 110(operation 1060).

To supply carbon dioxide gas to the carbonated water tank 110, therefrigerator 1 may close the purified water supply valve 131 and thecarbon dioxide gas discharge valve 113, and then may open the carbondioxide gas supply valve 152 for a predetermined carbon dioxide gassupply time.

As illustrated in FIG. 14, when the carbon dioxide gas supply valve 152is opened, carbon dioxide gas may be supplied to the carbonated watertank 110 from the carbon dioxide gas cylinder 120 along the carbondioxide gas supply flow path 150. In addition, carbon dioxide gas may besupplied to the carbonated water tank 110 after the pressure is reducedby the carbon dioxide gas regulator 151.

The refrigerator 1 may wait for a carbon dioxide dissolution time todissolve carbon dioxide gas in purified water (operation 1070).

Despite of supplying carbon dioxide gas to the carbonated water tank 110where purified water is filled, carbon dioxide gas may be notimmediately dissolved. It may require from several minutes to severalten minutes to dissolve sufficient amount of carbon dioxide gas inpurified water, but there may be differences according to the pressureof carbon dioxide gas, the concentration of carbon dioxide gas dissolvedin purified water, and the likes.

When the carbon dioxide gas dissolution time is expired after supplyingcarbon dioxide gas, the refrigerator 1 may determine whether theconcentration of carbonated water stored in the carbonated water tank110 reaches a target concentration (operation 1080).

For example, to determine whether the concentration of carbonated waterstored in the carbonated water tank 110 reaches a target concentration,the refrigerator 1 may determine whether the concentration of carbonatedwater reaches a target concentration based on a supply time of a carbondioxide gas supplied to the carbonated water tank 110. This is because acertain pressure of carbon dioxide gas is supplied to the carbonatedwater tank by the carbon dioxide gas regulator 151.

For another example, the refrigerator 1 may determine whether theconcentration of carbon dioxide gas reaches the target concentrationbased on the number of supplying time of carbon dioxide gas to thecarbonated water tank 110.

The carbon dioxide gas pressure of the inside of the carbonated watertank 110 may be limited below a certain pressure, and thus therefrigerator 1 may repeatedly supply carbon dioxide gas and dissolvecarbon dioxide gas to dissolve a large amount of carbon dioxide gas inpurified water.

In other words, the refrigerator 1 may change the number of supplyingtime of carbon dioxide gas according to a target concentration inputtedby the user.

The refrigerator 1 may supply carbon dioxide gas by only one time toproduce carbonated water at a low concentration, may supply carbondioxide gas by dividing two times to produce carbonated water at amiddle concentration, and may supply carbon dioxide gas by dividingthree times to produce carbonated water at a high concentration.

Depending on the number of supplying times, the carbon dioxide gassupply time and the carbon dioxide gas dissolution time may be variable.

When the first supply of carbon dioxide gas, carbon dioxide gas may besupplied for 6 seconds, and may be dissolved for 4 minutes, when thesecond supply of carbon dioxide gas, carbon dioxide gas may be suppliedfor 4 seconds, and may be dissolved for 8 minutes, and the third supplyof carbon dioxide gas, carbon dioxide gas may be supplied for 5.5seconds, and may be dissolved for 12 minutes.

The refrigerator 1 may change the amount of carbon dioxide gas dissolvedin purified water by changing the number of supplying time of carbondioxide gas, and the supply time of carbon dioxide gas.

Accordingly, to determine whether the carbonated water concentrationreaches the target concentration, the refrigerator 1 may determinewhether the number of supplying times of carbon dioxide gas supplied tothe carbonated water tank 110 corresponds to the number of supplyingtime of carbon dioxide gas according to the target concentration.

When it is determined that the concentration of the carbonated waterdoes not reach the target concentration (NO of operation 1080), therefrigerator 1 may repeatedly supply carbon dioxide gas and dissolvecarbon dioxide gas to the carbonated water tank 110.

When it is determined that the concentration of the carbonated waterreaches the target concentration (YES of operation 1080), therefrigerator 1 may display the completion of the carbonated waterproduction on the user interface 300 (operation 1090).

For example, the refrigerator 1 may display a completion of thecarbonated water production image on the carbonated water productiondisplaying unit 313 included in the carbonated water producingactivation unit 310.

As mentioned above, the refrigerator 1 may produce carbonated water atvarious concentrations by using the carbonated water production module100.

FIG. 15 is a view illustrating a method of discharging carbonated waterof a refrigerator according to one embodiment of the present disclosureand FIG. 16 is a view illustrating an example of discharging carbonatedwater by a refrigerator according to the method illustrated in FIG. 15.

A method of discharging carbonated water 1100 of a refrigerator 1 willbe described with reference to FIGS. 15 and 16.

The refrigerator 1 may determine whether a command of dischargingcarbonated water is inputted (operation 1110).

When a user presses the dispenser lever 93 to discharge carbonatedwater, the refrigerator 1 may determine that a command of dischargingcarbonated water is inputted.

For example, when the third lever 93 c included in the dispenser lever93 is located in the fifth position P5, and the second lever 93 b ismoved from the third position P3 to the fourth position P4, therefrigerator 1 may determine that the command of discharging carbonatedwater is inputted.

When the command of discharging carbonated water is not inputted (NO ofoperation 1110), the refrigerator 1 may continue to perform an operationpreviously performed.

When the command of discharging carbonated water is inputted (YES ofoperation 1110), the refrigerator 1 may discharge carbonated water viathe dispenser module 90 (operation 1120).

Particularly, the refrigerator 1 may open the residual water dischargeprevention valve 191 and the carbonated water discharge valve 135 insequence to discharge carbonated water. When the residual waterdischarge prevention valve 191 and the carbonated water discharge valve135 are opened, carbonated water stored in the carbonated water tank 110may be discharged along the carbonated water discharge flow path 180 andthe integrated discharge flow path 190 by the pressure of carbon dioxidegas remained the carbonated water tank 110, as illustrated in FIG. 16.

That is, carbonated water may be discharged to the carbonated water tank110 by the pressure difference between the internal pressure of thecarbonated water tank 110 and the external pressure of the carbonatedwater tank 110.

The refrigerator 1 may estimate an amount of remaining carbonated water(operation 1130).

The amount of remaining carbonated water may represent an amount ofcarbonated water remaining in the carbonated water tank 110, and theamount of remaining carbonated water may be estimated based on thecapacity of the carbonated water tank 110 and an accumulated amount ofdischarged carbonated water, that is, a sum of discharged carbonatedwater from when carbonated water is produced.

Carbonated water may be discharged at a certain pressure by thecarbonated water regulator 181. Therefore, the refrigerator 1 mayestimate an amount of remaining carbonated water stored in thecarbonated water tank 110 based on a total open period of time of thecarbonated water discharge valve 135, that is, a cumulative dischargetime of carbonated water, and an output pressure of the carbonated waterregulator 181.

For example, in a state where the capacity of the carbonated water tank110 is the same as an amount of carbonated water discharged for 1minute, the refrigerator 1 may determine that an amount of remainingcarbonated water is more than ⅔ of the total capacity when a cumulativedischarge time of carbonated water is less than 20 seconds. In addition,when a cumulative discharge time of carbonated water is from 20 to 40seconds, the refrigerator 1 may determine that an amount of remainingcarbonated water is from ⅓ to ⅔ of the total capacity, and when acumulative discharge time of carbonated water is longer than 40 seconds,the refrigerator 1 may determine that an amount of remaining carbonatedwater is less than ⅓ of the total capacity.

The refrigerator 1 may display the amount of remaining carbonated wateron the user interface 300 (operation 1140).

The refrigerator 1 may display the amount of remaining carbonated water,which is estimated at a step 1130, on the carbonated water leveldisplaying unit 340. For example, when the amount of remainingcarbonated water is more than ⅔ of the total capacity, the refrigerator1 may display three water level displaying bars on the carbonated waterlevel displaying unit 340, when the amount of remaining carbonated wateris from ⅓ to ⅔ of the total capacity, the refrigerator 1 may display twowater level displaying bars on the carbonated water level displayingunit 340, and when the amount of remaining carbonated water is less than⅓ of the total capacity, the refrigerator 1 may display one water leveldisplaying bar on the carbonated water level displaying unit 340.

The refrigerator 1 may determine whether inputting of the command ofdischarging carbonated water is stopped (operation 1150).

When the user releases the dispenser lever 93, the refrigerator 1 maydetermine that inputting of the command of discharging carbonated wateris stopped.

For example, when the second lever 93 b included in the dispenser module90 is moved from the fourth position P4 to the third position P3, therefrigerator 1 may determine that inputting of the command ofdischarging carbonated water is stopped.

When the command of discharging carbonated water is continued (NO ofoperation 1150), the refrigerator 1 may repeat the estimation and thedisplay of the amount of remaining carbonated water.

When the command of discharging carbonated water is stopped (YES ofoperation 1150), the refrigerator 1 may stop discharging carbonatedwater (operation 1160).

The refrigerator 1 may close the carbonated water discharge valve 135and the residual water discharge prevention valve 191 in sequence tostop discharging carbonated water.

After discharging carbonated water is stopped, the refrigerator 1 maydetermine whether the amount of remaining carbonated water is less thanthe minimum amount of carbonated water (operation 1170).

The minimum amount of carbonated water may represent an amount ofcarbonated water corresponding to the lowest water level of carbonatedwater stored in the carbonated water tank 110. The minimum amount ofcarbonated water may be various according to the carbonated water tank110, and may be set to “0”.

When the amount of remaining carbonated water is less than the minimumamount of carbonated water (YES of operation 1170), the refrigerator 1may start to produce carbonated water (operation 1180).

Particularly, the refrigerator 1 may produce carbonated water bysupplying purified water and carbon dioxide gas to the carbonated watertank 110.

When the amount of remaining carbonated water is larger than the minimumamount of carbonated water (NO of operation 1170), the refrigerator 1may store the amount of remaining carbonated water (operation 1190).

The refrigerator 1 may store the amount of remaining carbonated water inthe memory 520 of the controller 500 or the storage 400 to estimate theamount of remaining carbonated water when carbonated water isdischarged.

As mentioned above, the refrigerator 1 according to one embodiment mayestimate the amount of discharged carbonated water based on thecarbonated water discharge time, and may display the amount of remainingcarbonated water stored in the carbonated water tank 110 based on theestimated amount of discharged carbonated water.

FIG. 17 is a view illustrating a method of discharging purified water ofa refrigerator according to one embodiment of the present disclosure andFIG. 18 is a view illustrating an example of discharging purified waterby a refrigerator according to the method illustrated in FIG. 17.

A method of discharging purified water 1200 of a refrigerator 1 will bedescribed with reference to FIGS. 17 and 18.

The refrigerator 1 may determine whether a command of dischargingpurified water is inputted (operation 1210).

When a user presses the dispenser lever 93 to discharge purified water,the refrigerator 1 may determine that a command of discharging purifiedwater is inputted.

For example, when the first lever 93 a included in the dispenser lever93 is moved from the first position P1 to the second position P2, therefrigerator 1 may determine that a command of discharging purifiedwater is inputted.

When the command of discharging purified water is not inputted (NO ofoperation 1210), the refrigerator 1 may continue to perform an operationpreviously performed.

When the command of discharging purified water is inputted (YES ofoperation 1210), the refrigerator 1 may discharge purified water via thedispenser module 90 (operation 1220).

Particularly, the refrigerator 1 may open the residual water dischargeprevention valve 191 and the purified water discharge valve 133 insequence to discharge purified water.

When the residual water discharge prevention valve 191 and the purifiedwater discharge valve 133 are opened, purified water stored in thepurified water tank 71 may be discharged along the first purified watersupply flow path 160 and the integrated discharge flow path 190 to theoutside by the water pressure of the external water source 40, asillustrated in FIG. 18.

The refrigerator 1 may determine whether the amount of dischargedpurified water is larger than the reference amount of dischargedpurified water (operation 1230).

The refrigerator 1 may detect the amount of discharge purified water.

Since purified water is discharged by the water pressure of the externalwater source 40, the amount of discharged purified water discharged bythe dispenser module 90 may be the same as the amount of suppliedpurified water from the external water source 40 to the purified watersupply module 70. In addition, the refrigerator 1 may estimate theamount of supplied purified water supplied from the external watersource 40 to the purified water supply module 70 by using the flowsensor 77.

Therefore, the refrigerator 1 may detect the amount of dischargedpurified water by using the flow sensor 77.

The refrigerator 1 may compare the detected amount of dischargedpurified water with the reference amount of discharged purified water.

The reference amount of discharged water may be determined as the amountof water corresponding to a cup of water, but is not limited thereto.The reference amount of discharged water may be variously set accordingto the application. Also, the reference amount of discharged water maybe set via the user interface 300 by a user.

When the amount of discharged purified water is less than the referenceamount of discharged water (NO of operation 1230), the refrigerator 1may determine whether inputting of the command of discharging purifiedwater is stopped (operation 1240).

Particularly, when the user releases the dispenser lever 93, therefrigerator 1 may determine that inputting of the command ofdischarging purified water is stopped.

For example, when the first lever 93 a included in the dispenser module90 is moved from the second position P2 to the first position P1, therefrigerator 1 may determine that inputting of the command ofdischarging purified water is stopped.

When inputting of the command of discharging purified water is continued(YES of operation 1240), the refrigerator 1 may repeat the discharge ofpurified water, the estimation of the amount of discharged purifiedwater, and the comparison of the amount of discharged purified waterwith the reference amount of discharged water.

When the amount of discharged purified water is larger than thereference amount of discharged water (YES of operation 1230) orinputting of the command of discharging purified water is stopped (YESof operation 1240), the refrigerator 1 may stop discharging purifiedwater (operation 1250).

Particularly, the refrigerator 1 may close the purified water dischargevalve 133 and the residual water discharge prevention valve 191 insequence to stop discharging purified water.

As mentioned above, the refrigerator 1 according to one embodiment maydetect the amount of discharged purified water during the discharge ofpurified water, and may prevent the amount of discharged purified waterfrom being exceeded the reference amount of discharged water.

FIG. 19 is a view illustrating a method of supplying water for makingice by a refrigerator according to one embodiment of the presentdisclosure and FIG. 20 is a view illustrating an example of supplyingpurified water to an ice maker in a refrigerator according to a methodillustrated in FIG. 19.

A method of supplying water for making ice 1300 in which a refrigerator1 supplies purified water to an ice maker 81 will be described withreference to FIGS. 19 and 20.

The refrigerator 1 may determine whether conditions for making ice aresatisfied (operation 1310).

When ice is discharged from the ice making tray included in the icemaker 81 to the ice bucket, the refrigerator 1 may perform operations ofice making to produce new ice.

When the conditions for making ice are not satisfied (NO of operation1310), the refrigerator 1 may continue to perform an operationpreviously performed.

When the conditions for making ice are satisfied (YES of operation1310), the refrigerator 1 may supply purified water to the ice marker 81(operation 1320).

The refrigerator 1 may switch a flow path of purified water to the icemaker 81 to supply purified water to the ice maker 81.

When the operation of making ice is not required, in order to supplypurified water to the purified water tank 71, the refrigerator 1 mayopen a flow path on the side of the purified water tank 71 and maycontrol the flow path switching valve 75 to close a flow path on theside of the ice maker 81.

Meanwhile, when the operation of making ice is required, in order tosupply purified water to the ice maker 81, the refrigerator 1 may closea flow path on the side of the purified water tank 71 and may controlthe flow path switching valve 75 to open a flow path on the side of theice maker 81.

When the flow path on the side of the ice maker 81 is opened, purifiedwater purified by the purification filter 73 may be supplied to the icemaker 81 via the flow path switching valve 175, as illustrated in FIG.20.

The refrigerator 1 may determine whether the amount of purified watersupplied to the ice maker 81 is larger than the reference amount ofwater for making ice (operation 1330).

The refrigerator 1 may detect the amount of purified water supplied tothe ice maker 81 by the flow sensor 77.

When the flow path on the side of the ice maker 81 is opened, purifiedwater may be supplied to the ice maker 81 from the external water source40 via the flow sensor 77, the purification filter 73, and the flow pathswitching valve 75, and the refrigerator 1 may estimate the amount ofpurified water supplied from the external water source 40 to thepurified supply module 70 by the flow sensor 77.

Therefore, the refrigerator 1 may detect the amount of purified watersupplied to the ice maker 81 by using the flow sensor 77.

In addition, the refrigerator 1 may compare the detected amount ofsupplied purified water with the reference amount of supplied water formaking ice. Here, the reference amount of supplied water for making icemay determine the amount of water storable in the ice making tray.

When the amount of supplied purified water for making ice is less thanthe reference amount of supplied water for making ice (NO of operation1330), the refrigerator 1 may continue to supply purified water to theice maker 81.

When the amount of supplied purified water for making ice is larger thanthe reference amount of supplied water for making ice (YES of operation1330), the refrigerator 1 may stop supplying purified water to the icemaker 81 (operation 1340).

To stop supplying purified water to the ice maker 81, the refrigerator 1may switch a flow path of purified water to the purified water tank 71.Particularly, the refrigerator 1 may open a flow path on the side of thepurified water tank 71 and may control the flow path switching valve 175to close a flow path on the side of the ice maker 81.

As mentioned above, the refrigerator 1 according to one embodiment maydetect the amount of supplied purified water for making ice and mayprevent the amount of supplied purified water from being exceeded thereference amount of supplied water for making ice.

FIG. 21 is a view illustrating a method of determining water leakage ofa refrigerator according to one embodiment of the present disclosure andFIGS. 22 and 23 are views illustrating an example of detecting waterleakage in a purified water supply module or a carbonated waterproduction module by a refrigerator according to a method illustrated inFIG. 21.

A method of determining water leakage 1400 in which the refrigerator 1detects the location of water leakage in the purified water supplymodule 70 and the carbonated water production module 100 will bedescribed with reference to FIGS. 21 to 23.

The refrigerator 1 may determine whether water leakage is detected inthe carbonated water production module 100 (operation 1405).

The refrigerator 1 may determine whether water leakage occurs by usingvarious manners.

For example, the refrigerator 1 may detect water leakage in thecarbonated water production module 100 by using the water leakage sensor147 included in the carbonated water production module 100.Particularly, when the current flows on a pair of electrodes included inthe water leakage sensor 147, the refrigerator 1 may determine thatwater leakage occurs in the carbonated water production module 100.

For another example, when the flow of water is detected by the flowsensor 77 in a state where the production of the carbonated water or thedischarge of the purified water is not performed, the refrigerator 1 maydetermine that water leakage occurs in the carbonated water productionmodule 100.

When water leakage in the carbonated water production module 100 isdetermined by the flow sensor 77, the refrigerator 1 may not include thewater leakage sensor 147.

When the water leakage is not detected (NO of operation 1405), therefrigerator 1 may continue to perform an operation previouslyperformed.

When the water leakage is detected (YES of operation 1405), therefrigerator 1 may close a plurality of valves 131, 133, and 135included in the valve assembly 130 (operation 1410).

The refrigerator 1 may close the purified water supply valve 131, thepurified water discharge valve 133, and the carbonated water dischargevalve 135 all of which are included in the valve assembly 130 todetermine whether water leakage occurs in the first purified watersupply flow path 160.

When the purified water supply valve 131, the purified water dischargevalve 133, and the carbonated water discharge valve 135 are closed,purified water may fill the flow path to an upper portion of thepurified water supply valve 131, as illustrated in FIG. 22.

The refrigerator 1 may detect the flow of water by using the flow sensor77 (operation 1420).

When the purified water supply valve 131, the purified water dischargevalve 133, and the carbonated water discharge valve 135 are closed,purified water may supply to an upper portion of the purified watersupply valve 131, but may not flow.

When the flow of water is detected (YES of operation 1420), therefrigerator 1 may warn the water leakage of the first purified watersupply flow path 160 or the valve assembly 130 (operation 1425).Particularly, the refrigerator 1 may warn the water leakage of the firstpurified water supply flow path 160 via the user interface 300.

When the purified water supply valve 131, the purified water dischargevalve 133, and the carbonated water discharge valve 135 are closed,purified water may be supplied to the first purified water supply flowpath 160 of the carbonated water production module 100, as illustratedin FIG. 22.

Therefore, when the flow sensor 77 detects the flow of water despite ofclosing the purified water supply valve 131, the purified waterdischarge valve 133, and the carbonated water discharge valve 135, therefrigerator 1 may determine that water leakage occurs in the firstpurified water supply flow path 160 or at a coupling part between thefirst purified water supply flow path 160 and the valve assembly 130.

When the flow of water is not detected (NO of operation 1420), therefrigerator 1 may open the purified water supply valve 131 (operation1430).

when the flow of water is not detected in a state where the purifiedwater supply valve 131, the purified water discharge valve 133, and thecarbonated water discharge valve 135 are closed, the refrigerator 1 maydetermine that water leakage does not occur in the first purified watersupply flow path 160 or in the purified water supply valve 131.

Therefore, the refrigerator 1 may open the purified water supply valve131 to determine whether water leakage occurs in a lower portion of thepurified water supply valve 130.

When the purified water supply valve 131 is opened, purified water mayfill to an upper portion of the carbonated water discharge valve 135, asillustrated in FIG. 23.

The refrigerator 1 may detect the flow of water by using the flow sensor77 (operation 1440).

When the purified water discharge valve 133 and the carbonated waterdischarge valve 135 are closed, purified water may be supplied to onlythe carbonated water tank 110, but may not flow. This is becausepurified water is not supplied to the carbonated water tank 110 bycarbon dioxide gas inside the carbonated water tank 110 for thedischarge of the carbonated water.

When the flow of water is detected (YES of operation 1440), therefrigerator 1 may warn the water leakage of the second purified watersupply flow path 170 or the valve assembly 130 (operation 1445).Particularly, the refrigerator 1 may warn the water leakage of thesecond purified water supply flow path 170 via the user interface 300.

When the purified water discharge valve 133 and the carbonated waterdischarge valve 135 are closed, purified water may be supplied to thesecond purified water supply flow path 170 of the carbonated waterproduction module 100, as illustrated in FIG. 22.

Therefore, when the flow sensor 77 detects the flow of water despite ofclosing the purified water discharge valve 133, and the carbonated waterdischarge valve 135, the refrigerator 1 may determine that water leakageoccurs in the first purified water supply flow path 160, in a couplingpart between the first purified water supply flow path 160 and the valveassembly 130 or in a coupling part between the first purified watersupply flow path 160 and the carbonated water tank 110.

When the flow of water is not detected (NO of operation 1440), therefrigerator 1 may warn the water leakage of the carbonated water flowpath (operation 1450).

As mentioned above, when it is determined that water leakage does notoccur in the first purified water supply flow path 160 and the secondpurified water supply flow path 170, the refrigerator 1 may determinethat water leakage occurs in the carbonated water discharge flow path180, in a coupling part between the carbonated water discharge flow path180 and the carbonated water tank 110, or in a coupling part between thecarbonated water discharge flow path 180 and the carbonated waterdischarge valve 135. This is because water leakage may occur in thecarbonated water discharge valve 180 without supplying water from theexternal water source 40 since carbonated water is stored in thecarbonated water tank 110.

Therefore, the refrigerator 1 may warn the water leakage in thecarbonated water discharge valve 180 via the user interface 300.

As mentioned above, when it is determined that water leakage occurs inthe carbonated water production module 100, the refrigerator 1 maydetermine a location where water leakage occurs based on opening/closingthe valves 131, 133, and 135 included in the valve assembly 130 and theresult of detection of the flow of water by the flow sensor 77.

FIG. 24 is a view illustrating a method of determining an abnormality ina purified water supply valve of a refrigerator according to oneembodiment of the present disclosure.

A method of determining an abnormality in the purified water supplyvalve 1500 in which the refrigerator 1 determines an abnormality in thepurified water supply valve 131 will be described with reference to FIG.24.

The refrigerator 1 may determine whether purified water is supplied tothe carbonated water tank 110 (operation 1510).

The refrigerator 1 may determine whether purified water is supplied tothe carbonated water tank 110 based on a control signal provided to thepurified water supply valve 131.

Particularly, when an open valve signal is provided to the purifiedwater supply valve 131, the refrigerator 1 may determine that purifiedwater is supplied to the carbonated water tank 110, and when a closevalve signal is provided to the purified water supply valve 131, therefrigerator 1 may determine that purified water is not supplied to thecarbonated water tank 110.

When it is determined that purified water is supplied to the carbonatedwater tank 110 (YES of operation 1510), the refrigerator 1 may detectthe supply of the purified water by using the flow sensor 77 (operation1520).

When the purified water supply valve 131 is opened, the flow sensor 77may detect the supply of the purified water since purified water issupplied to the carbonated water tank 110 by the water pressure of theexternal water source 40.

When the supply of the purified water is detected (YES of operation1520), the refrigerator 1 may determine that there is no abnormality inthe operation of the purified water supply valve 131.

Conversely, when the supply of the purified water is not detected (NO ofoperation 1520), the refrigerator 1 may warn the abnormality of thepurified water supply valve (operation 1530).

What the flow sensor 77 does not detect the supply of the purified watermay represent that the purified water supply valve 131 is not opened.That is, since the purified water supply valve 131 is not openedalthough the open valve signal is provided to the purified water supplyvalve 131, the refrigerator 1 may determine that there is an abnormalityin the purified water supply valve 131.

The refrigerator 1 may warn the abnormality in the purified water supplyvalve 131 to a user via the user interface 300.

When it is determined that purified water is not supplied to thecarbonated water tank 110 (NO of operation 1510), the refrigerator 1 maydetect the supply of the purified water by using the flow sensor 77(operation 1540).

When the purified water supply valve 131 is normally operated in a statewhere the close valve signal is provided to the purified water supplyvalve 131, the supply of the purified water may be not detected.

When the supply of the purified water is not detected (NO of operation1540), the refrigerator 1 may determine that there is no abnormality inthe operation of the purified water supply valve 131.

When the supply of the purified water is detected (YES of operation1540), the refrigerator 1 may warn the abnormality of the purified watersupply valve 131 (operation 1550).

What the flow sensor 77 detects the supply of the purified water mayrepresent that the purified water supply valve 131 is not closed. Thatis, since the purified water supply valve 131 is not closed although theclose valve signal is provided to the purified water supply valve 131,the refrigerator 1 may determine that there is an abnormality in thepurified water supply valve 131.

The refrigerator 1 may warn the abnormality in the purified water supplyvalve 131 to a user via the user interface 300.

As mentioned above, the refrigerator 1 may determine the presence of theabnormality in the purified water supply valve 131 by using the flowsensor 77.

FIG. 25 is a view illustrating a method of determining an abnormality ina purified water discharge valve of a refrigerator according to oneembodiment of the present disclosure.

A method of determining an abnormality in the purified water dischargevalve 1600 in which the refrigerator 1 determines an abnormality in thepurified water discharge valve 133 will be described with reference toFIG. 25.

The refrigerator 1 may determine whether purified water is discharged(operation 1610).

The refrigerator 1 may determine whether purified water is dischargedbased on a control signal provided to the purified water discharge valve133.

Particularly, when an open valve signal is provided to the purifiedwater discharge valve 133, the refrigerator 1 may determine thatpurified water is discharged, and when a close valve signal is providedto the purified water discharge valve 133, the refrigerator 1 maydetermine that purified water is not discharged.

When it is determined that purified water is discharged (YES ofoperation 1610), the refrigerator 1 may detect the discharge of thepurified water by using the flow sensor 77 (operation 1620).

When the purified water discharge valve 133 is opened, the flow sensor77 may detect the discharge of the purified water since purified wateris discharged via the dispenser module 90 by the water pressure of theexternal water source 40.

When the discharge of the purified water is detected (YES of operation1620), the refrigerator 1 may determine that there is no abnormality inthe operation of the purified water discharge valve 133.

Conversely, the discharge of the purified water is not detected (NO ofoperation 1620), the refrigerator 1 may warn the abnormality in thepurified water discharge valve 133 (operation 1630).

What the flow sensor 77 does not detect the discharge of the purifiedwater may represent that the purified water discharge valve 133 is notopened. That is, since the purified water discharge valve 133 is notopened although the open valve signal is provided to the purified waterdischarge valve 133, the refrigerator 1 may determine that there is anabnormality in the purified water discharge valve 133.

The refrigerator 1 may warn the abnormality in the purified waterdischarge valve 133 to a user via the user interface 300.

When it is determined that purified water is not discharged (NO ofoperation 1610), the refrigerator 1 may detect the discharge of thepurified water by using the flow sensor 77 (operation 1640).

When the purified water supply valve 131 is normally operated in a statewhere the close valve signal is provided to the purified water dischargevalve 133, the discharge of the purified water may be not detected.

When the discharge of the purified water is not detected (NO ofoperation 1640), the refrigerator 1 may determine that there is noabnormality in the operation of the purified water discharge valve 133.

When the discharge of the purified water is detected (YES of operation1640), the refrigerator 1 may warn the abnormality in the purified waterdischarge valve 133 (operation 1650).

What the flow sensor 77 detects the discharge of the purified water mayrepresent that the purified water discharge valve 133 is not closed.That is, since the purified water discharge valve 133 is not closedalthough the close valve signal is provided to the purified waterdischarge valve 133, the refrigerator 1 may determine that there is anabnormality in the purified water discharge valve 133.

The refrigerator 1 may warn an abnormality in the purified waterdischarge valve 133 to a user via the user interface 300.

As mentioned above, the refrigerator 1 may determine the presence of theabnormality of the purified water discharge valve 133 by using the flowsensor 77.

FIG. 26 is a view illustrating a method of determining an abnormality ina carbonated water discharge valve of a refrigerator according to oneembodiment of the present disclosure;

A method of determining an abnormality in the carbonated water dischargevalve 1700 in which the refrigerator 1 determines an abnormality in thecarbonated water discharge valve 135 will be described with reference toFIG. 26.

The refrigerator 1 may determine whether carbonated water is dischargedfrom the carbonated water tank 110 (operation 1710).

The refrigerator 1 may determine whether carbonated water is dischargedbased on a control signal provided to the carbonated water dischargevalve 135.

Particularly, when an open valve signal is provided to the carbonatedwater discharge valve 135, the refrigerator 1 may determine thatcarbonated water is discharged, and when a close valve signal isprovided to the carbonated water discharge valve 135, the refrigerator 1may determine that carbonated water is not discharged.

When it is determined that carbonated water is discharged (YES ofoperation 1710), the refrigerator 1 may determine whether the internalpressure of the carbonated water tank 110 is reduced (operation 1720).

The refrigerator 1 may detect the internal pressure of the carbonatedwater tank 110 per a predetermined cycle by using the carbonated watertank pressure sensor 112, and may compare the currently detectedinternal pressure with the previously detected internal pressure.

When carbonated water is discharged due to opening of the carbonatedwater discharge valve 135, the internal pressure of the carbonated watertank 110 may be reduced since the carbonated water tank 110 is filledwith carbonated water and carbon dioxide gas.

When the internal pressure of the carbonated water tank 110 is reduced(YES of operation 1720), the refrigerator 1 may determine that there isno abnormality in the operation of the carbonated water discharge valve135.

When the internal pressure of the carbonated water tank 110 is notreduced (NO of operation 1720), the refrigerator 1 may warn theabnormality in the carbonated water discharge valve 135 (operation1730).

What the internal pressure of the carbonated water tank 110 is notreduced may represent that carbonated water is not discharged from thecarbonated water tank 110. That is, since the carbonated water dischargevalve 135 is not opened although the open valve signal is provided tothe carbonated water discharge valve 135, the refrigerator 1 maydetermine that there is an abnormality in the carbonated water dischargevalve 135.

The refrigerator 1 may warn the abnormality in the carbonated waterdischarge valve 135 to a user via the user interface 300.

When it is determined that carbonated water is not discharged (NO ofoperation 1710), the refrigerator 1 may determine whether the internalpressure of the carbonated water tank 110 is reduced (operation 1740).

The refrigerator 1 may detect the internal pressure of the carbonatedwater tank 110 per a predetermined cycle by using the carbonated watertank pressure sensor 112, and may compare the currently detectedinternal pressure with the previously detected internal pressure.

When the carbonated water discharge valve 135 is closed, the internalpressure of the carbonated water tank 110 may be constantly kept sincethe carbonated water tank 110 is filled with carbonated water and carbondioxide gas.

When the internal pressure of the carbonated water tank 110 is notreduced (NO of operation 1740), the refrigerator 1 may determine thatthere is no abnormality in the operation of the carbonated waterdischarge valve 135.

When the internal pressure of the carbonated water tank 110 is reduced(YES of operation 1740), the refrigerator 1 may warn the abnormality inthe carbonated water discharge valve 135 (operation 1750).

What the internal pressure of the carbonated water tank 110 is reducedmay represent that carbonated water is discharged from the carbonatedwater tank 110. That is, since the carbonated water discharge valve 135is not closed although the close valve signal is provided to thecarbonated water discharge valve 135, the refrigerator 1 may determinethat there is the abnormality in the carbonated water discharge valve135.

As mentioned above, the refrigerator 1 may determine the presence of theabnormality of the carbonated water discharge valve 135 by using thecarbonated water tank pressure sensor 112 provided on the carbonatedwater tank 110.

FIG. 27 is a view illustrating a method of determining the change ofcarbon dioxide gas cylinder of a refrigerator according to oneembodiment of the present disclosure.

A method of determining the change of a carbon dioxide gas cylinder 1800in which a refrigerator 1 determines whether to change the carbondioxide gas cylinder will be described with reference to FIG. 27.

The refrigerator 1 may determine whether a pressure of supplied carbondioxide gas is higher than the reference supply pressure (operation1810).

The refrigerator 1 may detect the pressure of supplied carbon dioxidegas by using various manners.

For example, the refrigerator 1 may detect the pressure of suppliedcarbon dioxide gas of the carbon dioxide gas cylinder 120 by using thecarbon dioxide gas pressure sensor 154.

Particularly, the refrigerator 1 may detect the pressure of suppliedcarbon dioxide gas of the carbon dioxide gas cylinder 120 by using thecarbon dioxide gas pressure sensor 154, and may determine whether thepressure of supplied carbon dioxide gas is higher than the referencesupply pressure by comparing the detected pressure of supplied carbondioxide gas with the reference supply pressure.

When the carbon dioxide gas pressure sensor 154 employs a pressureswitch, the refrigerator 1 may determine whether the pressure ofsupplied carbon dioxide gas is higher than the reference supply pressuredepending on a low-pressure signal outputted from the carbon dioxide gaspressure sensor 154.

For another example, the refrigerator 1 may detect the pressure ofsupplied carbon dioxide gas of the carbon dioxide gas cylinder 120 byusing the carbonated water tank pressure sensor 112.

Particularly, to produce the carbonated water, the refrigerator 1 maydetect the internal pressure of the carbonated water tank 110 by usingthe carbonated water tank pressure sensor 112 just after supplyingcarbon dioxide gas to the carbonated water tank 110.

Just after supplying carbon dioxide gas, the refrigerator 1 may estimatethe pressure of supplied carbon dioxide gas of the carbon dioxide gascylinder 120 according to the detected internal pressure of thecarbonated water tank 110. When the internal pressure of the carbonatedwater tank 110 detected just after supplying carbon dioxide gas is lowerthan the reference pressure, the refrigerator 1 may determine that thepressure of supplied carbon dioxide gas is lower than the referencesupply pressure, and when the internal pressure of the carbonated watertank 110 detected just after supplying carbon dioxide gas is higher thanthe reference pressure, the refrigerator 1 may determine that thepressure of supplied carbon dioxide gas is higher than the referencesupply pressure.

When the pressure of supplied carbon dioxide gas is higher than thereference supply pressure (YES of operation 1810), the refrigerator 1may continue to perform an operation previously performed.

When the pressure of supplied carbon dioxide gas is not higher than thereference supply pressure (NO of operation 1810), the refrigerator 1 maywarn the change of the carbon dioxide gas cylinder (operation 1820).

The carbonated water production module 100 may produce carbonated waterby supplying carbon dioxide gas after supplying purified water to thecarbonated water tank 110.

As mentioned above, the carbonated water production module 100 maysupply carbon dioxide gas at high pressure to the carbonated water tank110 to supply carbon dioxide gas to the carbonated water tank 110 inwhich purified water is supplied.

At this time, when the pressure of supplied carbon dioxide gas isreduced below the reference supply pressure, the amount of carbondioxide gas supplied to the carbonated water tank 110 may be reduced andthe quality of the carbonated water produced by the carbonated waterproduction module 110 may be degraded.

To prevent those difficulties, the refrigerator 1 may warn the change ofthe carbon dioxide gas cylinder 120 by using the user interface 300 whenthe pressure of supplied carbon dioxide gas is reduced below thereference supply pressure.

As mentioned above, the refrigerator 1 may warn the change of the carbondioxide gas cylinder 120 to maintain the constant quality of thecarbonated water when the pressure of supplied carbon dioxide gas isreduced below the reference supply pressure.

FIG. 28 is a view illustrating a method of determining an abnormality ina carbon dioxide supply/discharge valve of a refrigerator according toone embodiment of the present disclosure.

A method of determining an abnormality in the carbon dioxide gassupply/discharge valve 1900 in which the refrigerator 1 determines anabnormality in the carbon dioxide gas supply valve 152 and the carbondioxide gas discharge valve 113 will be described with reference to FIG.28.

The refrigerator 1 may determine whether carbon dioxide gas is suppliedto the carbonated water tank 110 (operation 1910).

The refrigerator 1 may determine whether carbon dioxide gas is suppliedbased on a control signal provided to the carbon dioxide gas supplyvalve 152 and the carbon dioxide gas discharge valve 113.

Particularly, when a close valve signal is provided to the carbondioxide gas discharge valve 113, and an open valve signal is provided tothe carbon dioxide gas supply valve 152, the refrigerator 1 maydetermine that carbon dioxide gas is supplied to the carbonated watertank 110. In addition, when a close valve signal is provided to thecarbon dioxide gas supply valve 152, the refrigerator 1 may determinethat carbon dioxide gas is not supplied.

When it is determined that carbon dioxide gas is not supplied (NO ofoperation 1910), the refrigerator 1 may continue to perform an operationpreviously performed.

When it is determined that carbon dioxide gas is supplied (YES ofoperation 1910), the refrigerator 1 may determine whether the internalpressure of the carbonated water tank 110 is increased (operation 1920).

The refrigerator 1 may detect the internal pressure of the carbonatedwater tank 110 per a predetermined cycle by using the carbonated watertank pressure sensor 112, and may compare the currently detectedinternal pressure with the previously detected internal pressure.

When the internal pressure of the carbonated water tank 110 is increased(YES of operation 1920), the refrigerator 1 may determine that there isno abnormality in the operation of the carbonated water discharge valve135.

When the internal pressure of the carbonated water tank 110 is notincreased (NO of operation 1920), the refrigerator 1 may warn anabnormality in the carbon dioxide gas supply valve 152 or the carbondioxide gas discharge valve 113 (operation 1930).

What the internal pressure of the carbonated water tank 110 is notincreased may represent that carbon dioxide gas is not supplied to thecarbonated water tank 110 from the carbon dioxide gas cylinder 120 orcarbon dioxide gas supplied to the carbonated water tank 110 is leaked.

That is, the carbon dioxide gas supply valve 152 may be not openedalthough the open valve signal is provided to the carbon dioxide gassupply valve 152 or the carbon dioxide gas discharge valve 113 may benot closed although the close valve signal is provided to the carbondioxide gas discharge valve 113.

Particularly, when the internal pressure of the carbonated water tank110 is not increased, the refrigerator 1 may determine the abnormalityin the carbon dioxide gas supply valve 152, and when the internalpressure of the carbonated water tank 110 is lower than the atmosphericpressure, the refrigerator 1 may determine the abnormality in the carbondioxide gas discharge valve 113.

The refrigerator 1 may warn an abnormality in the carbon dioxide gassupply valve 152 or the carbon dioxide gas discharge valve 113 via theuser interface 300.

As mentioned above, the refrigerator 1 may determine the presence of theabnormality in the carbon dioxide gas supply valve 152 or the carbondioxide gas discharge valve 113 by using the carbonated water tankpressure sensor 112.

FIG. 29 is a view illustrating a method of determining an abnormality ina carbon dioxide discharge valve of a refrigerator according to oneembodiment of the present disclosure.

A method of determining an abnormality in the carbon dioxide gasdischarge valve 2000 in which the refrigerator 1 determines anabnormality in the carbon dioxide gas discharge valve 113 will bedescribed with reference to FIG. 29.

The refrigerator 1 may determine whether carbon dioxide gas isdischarged from the carbonated water tank 110 (operation 2010).

The refrigerator 1 may determine whether carbon dioxide gas isdischarged based on a control signal provided to the carbon dioxide gasdischarge valve 113.

Particularly, when an open valve signal is provided to the carbondioxide gas discharge valve 113, the refrigerator 1 may determine thatcarbon dioxide gas is discharged and when a close valve signal isprovided to the carbon dioxide gas discharge valve 113, the refrigerator1 may determine that carbon dioxide gas is not discharged.

When it is determined that carbon dioxide gas is not discharge (NO ofoperation 2010), the refrigerator 1 may continue to perform an operationpreviously performed.

When it is determined that carbon dioxide gas is discharged (YES ofoperation 2010), the refrigerator 1 may determine whether the internalpressure of the carbonated water tank 110 is higher than the atmosphericpressure (operation 2020).

The refrigerator 1 may detect the internal pressure of the carbonatedwater tank 110 by using the carbonated water tank pressure sensor 112,and may compare the currently detected internal pressure with theatmospheric pressure.

When the carbon dioxide gas discharge valve 113 is opened and carbondioxide gas inside the carbonated water tank 110 is discharged to theoutside, the inside and the outside of the carbonated water tank 110 maybecome a pressure equilibrium state. That is, the internal pressure ofthe carbonated water tank 110 may be the same as the atmosphericpressure.

When the internal pressure of the carbonated water tank 110 is nothigher than the atmospheric pressure (NO of operation 2020), therefrigerator 1 may determine that there is no abnormality in theoperation of the carbon dioxide gas discharge valve 113.

When the internal pressure of the carbonated water tank 110 is higherthan the atmospheric pressure (YES of operation 2020), the refrigerator1 may warn an abnormality in the carbon dioxide gas discharge valve 113(operation 2030).

What the internal pressure of the carbonated water tank 110 is greatthan the atmospheric pressure may represent that carbon dioxide gas isnot discharged from the carbonated water tank 110. That is, since thecarbon dioxide gas discharge valve 113 is not opened although the openvalve signal is provided to the carbon dioxide gas discharge valve 113,the refrigerator 1 may determine that there is the abnormality in thecarbon dioxide gas discharge valve 113.

The refrigerator 1 may warn the abnormality in the carbon dioxide gasdischarge valve 113 to a user via the user interface 300.

As mentioned above, the refrigerator 1 may determine the presence of theabnormality in the carbon dioxide gas discharge valve 113 by using thecarbonated water tank pressure sensor 112 provided in the carbonatedwater tank 110.

FIG. 30 is a view illustrating a method of supplementing carbon dioxideof a refrigerator according to one embodiment of the present disclosure.

A method of supplementing carbon dioxide 2300 in which the refrigerator1 supplementally supplies carbon dioxide gas to the carbonated watertank 110 will be described with respect to FIG. 30.

The refrigerator 1 may determine whether the internal pressure of thecarbonated water tank 110 is higher than the minimum internal pressure(operation 2310).

The refrigerator 1 may detect the internal pressure of the carbonatedwater tank 110 by using the carbonated water tank pressure sensor 112,and may compare the currently detected internal pressure with theminimum internal pressure.

“the minimum internal pressure” may represent a minimum internalpressure to allow the carbonated water tank 110 to discharge carbonatedwater by using the internal pressure of the carbonated water tank 110.

When discharging the carbonated water, the carbonated water tank 110 maydischarge carbonated water by using the internal pressure of thecarbonated water tank 110. That is, the carbonated water tank 110 maydischarge carbonated water by using a difference between the internalpressure of the carbonated water tank 110 and the atmospheric pressure.

To discharge carbonated water at more than a certain pressure, therefrigerator 1 may maintain the internal pressure of the carbonatedwater tank 110 to be higher than the minimum internal pressure.

However, when the refrigerator 1 discharges carbonated water, theinternal pressure of the carbonated water tank 110 may be reduced. Inaddition, as time passes from when carbonated water is produced, theinternal pressure of the carbonated water tank 110 may be reduced sincecarbon dioxide gas is dissolved in carbonated water.

When the internal pressure of the carbonated water tank 110 is higherthan the minimum internal pressure (YES of operation 2310), therefrigerator 1 may continue to perform an operation performedpreviously.

When the internal pressure of the carbonated water tank 110 is nothigher than the minimum internal pressure (NO of operation 2310), therefrigerator 1 may supplementally supply carbon dioxide gas to thecarbonated water tank 110 without supplying purified water (operation2320).

The refrigerator 1 may open the carbon dioxide gas supply valve 152 fora predetermined supplement supply time to increase the internal pressureof the carbonated water tank 110. When the carbon dioxide gas supplyvalve 152 is opened, carbon dioxide gas may be additionally supplied tothe carbonated water tank 110, and the internal pressure of thecarbonated water tank 110 may be increased.

FIG. 31 is a view illustrating a method of discharging carbon dioxide ofa refrigerator according to one embodiment of the present disclosure.

A method of discharging carbon dioxide gas 2600 in which therefrigerator 1 discharges carbon dioxide gas to the carbonated watertank 110 will be described with reference to FIG. 31.

The refrigerator 1 may determine whether the internal pressure of thecarbonated water tank 110 is higher than the maximum internal pressure(operation 2610).

The refrigerator 1 may detect the internal pressure of the carbonatedwater tank 110 by using the carbonated water tank pressure sensor 112,and may compare the currently detected internal pressure with themaximum internal pressure.

“the minimum internal pressure” may represent a maximum value of theinternal pressure which is allowed by the carbonated water tank 110 forthe safety.

When supplying carbon dioxide gas to the carbonated water tank 110 tosupplement the internal pressure of the carbonated water tank 110 or toproduce carbonated water, carbon dioxide gas, which is more thanappropriate amount, may be supplied to the carbonated water tank 110 dueto the abnormality in the carbon dioxide gas supply valve 152 or thecarbon dioxide gas regulator 151.

In this case, it may cause safety problems in the carbonated water tank110.

When the internal pressure of the carbonated water tank 110 is lowerthan the maximum internal pressure (NO of operation 2610), therefrigerator 1 may continue to perform an operation previouslyperformed.

When the internal pressure of the carbonated water tank 110 is higherthan the maximum internal pressure (YES of operation 2610), therefrigerator 1 may discharge carbon dioxide gas from the carbonatedwater tank 110 (operation 2620).

The refrigerator 1 may open the carbon dioxide gas discharge valve 113for a predetermined discharge time to increase the internal pressure ofthe carbonated water tank 110. When the carbon dioxide gas dischargevalve 113 is opened, carbon dioxide gas may be discharged from thecarbonated water tank 110, and the internal pressure of the carbonatedwater tank 110 may be reduced.

As mentioned above, the refrigerator 1 may maintain the internalpressure of the carbonated water tank 110 within a predetermined range,after producing the carbonated water, by using the carbonated water tankpressure sensor 112.

FIG. 32 is a view illustrating a carbonated water production module anda purified water supply module of a refrigerator according to anotherembodiment of the present disclosure.

A purified water supply module 70′ and a carbonated water productionmodule 100′ included in a refrigerator 1′ according to anotherembodiment will be described with reference to FIG. 32. However, adescription of the same parts as the purified water supply module andthe carbonated water production module shown in FIG. 5 will be omitted.

As illustrated in FIG. 32, the purified water supply module 70′ mayinclude a purified water tank 71, a purification filter 73, a flow pathswitching valve 75, and a flow sensor 77, and the carbonated waterproduction module 100′ may include a carbonated water tank 110, a carbondioxide gas cylinder 120, a valve assembly 130, a variety of flow paths150, 160, 170, 180, and 190, and a module case 140.

The carbonated water tank 110 may include a pressure sensor 112, acarbon dioxide gas discharge valve 113, and a safety valve 114.

A first purified water supply flow path 160, a second purified watersupply flow path 170, a carbonated water discharge flow path 180 and anintegrated discharge flow path 190 may be provided among the carbonatedwater tank 110, the carbon dioxide gas cylinder 120, and the valveassembly 130.

In the integrated discharge flow path 190, a second flow sensor 193 todetect an amount of discharged carbonated water or an amount ofdischarged purified water via the integrated discharge flow path 190 maybe provided.

A configuration and an operation of the second flow sensor 193 is thesame as those of the first flow sensor 77 and thus a description thereofwill be omitted.

FIG. 33 is a view illustrating a method of discharging carbonated waterof a refrigerator according to another embodiment of the presentdisclosure and FIG. 34 is a view illustrating an example of dischargingcarbonated water by a refrigerator according to the method illustratedin FIG. 33.

A method of discharging carbonated water 2400 in which a refrigerator 1′discharges carbonated water will be described with reference to FIGS. 33and 34.

The refrigerator 1′ may determine whether a command of dischargingcarbonated water is inputted (operation 2410).

When a user presses the dispenser lever 93 to discharge carbonatedwater, the refrigerator 1′ may determine that a command of dischargingcarbonated water is inputted.

When the command of discharging carbonated water is not inputted (NO ofoperation 2410), the refrigerator 1′ may continue to perform anoperation previously performed.

When the command of discharging carbonated water is inputted (YES ofoperation 2410), the refrigerator 1′ may discharge carbonated water viathe dispenser module 90 (operation 2420).

Particularly, the refrigerator 1′ may open a residual water dischargeprevention valve 191 and a carbonated water discharge valve 135 insequence to discharge carbonated water. When the residual waterdischarge prevention valve 191 and the carbonated water discharge valve135 are opened, carbonated water stored in the carbonated water tank 110may be discharged along the carbonated water discharge flow path 180 andthe integrated discharge flow path 190 by a pressure of carbon dioxidegas remained the carbonated water tank 110, as illustrated in FIG. 34.

That is, carbonated water may be discharged to the carbonated water tank110 by the pressure difference between the internal pressure of thecarbonated water tank 110 and the external atmospheric pressure of thecarbonated water tank 110.

The refrigerator 1′ may estimate an amount of remaining carbonated water(operation 2430).

The amount of remaining carbonated water may represent an amount ofcarbonated water remaining in the carbonated water tank 110, and theamount of remaining carbonated water may be estimated based on thecapacity of the carbonated water tank 110 and an accumulated amount ofdischarged carbonated water, that is a sum of discharged carbonatedwater from when carbonated water is produced.

The refrigerator 1′ may estimate an accumulated amount of dischargedcarbonated water based on the result of the detection of the second flowsensor 193 provided on the integrated discharge flow path 190. When thecommand of discharging carbonated water is inputted, carbonated watermay be discharged to the outside via the second flow sensor 193, asillustrated in FIG. 34, and the second flow sensor 193 may detect theamount of discharged carbonated water while carbonated water isdischarged.

For example, when the command of discharging carbonated water isinputted, the refrigerator 1′ may count an electrical pulse outputted bythe second flow sensor 193, and may estimate an accumulated amount ofdischarged carbonated water based on the counted electrical pulse.

In addition, the refrigerator 1′ may estimate the amount of remainingcarbonated water based on a difference between the capacity of thecarbonated water tank 110 and the accumulated amount of dischargedcarbonated water.

The refrigerator 1′ may display the amount of remaining carbonated wateron the user interface 300 (operation 2440).

The refrigerator 1′ may display the amount of remaining carbonatedwater, which is estimated at a step 2430, on a carbonated water leveldisplaying unit 340. For example, when the amount of remainingcarbonated water is more than ⅔ of the total capacity, the refrigerator1′ may display three water level displaying bars on the carbonated waterlevel displaying unit 340, when the amount of remaining carbonated wateris from ⅓ to ⅔ of the total capacity, the refrigerator 1′ may displaytwo water level displaying bars on the carbonated water level displayingunit 340, and when the amount of remaining carbonated water is less than⅓ of the total capacity, the refrigerator 1′ may display one water leveldisplaying bar on the carbonated water level displaying unit 340.

The refrigerator 1′ may determine whether inputting of the command ofdischarging carbonated water is stopped (operation 2450).

When the user releases the dispenser lever 93, the refrigerator 1′ maydetermine that inputting of the command of discharging carbonated wateris stopped.

For example, when a second lever 93 b included in the dispenser module90 is moved from the fourth position P4 to the third position P3, therefrigerator 1′ may determine that inputting of the command ofdischarging carbonated water is stopped.

When the command of discharging carbonated water is continued (NO ofoperation 2450), the refrigerator 1′ may repeat the estimation and thedisplay of the amount of remaining carbonated water.

When the command of discharging carbonated water is stopped (YES ofoperation 2450), the refrigerator 1′ may stop discharging carbonatedwater (operation 2460).

The refrigerator 1′ may close the carbonated water discharge valve 135and the residual water discharge prevention valve 191 in sequence tostop discharging carbonated water.

After discharging carbonated water is stopped, the refrigerator 1′ maydetermine whether the amount of remaining carbonated water is less thanthe minimum amount of carbonated water (operation 2470).

The minimum amount of carbonated water may represent an amount ofcarbonated water corresponding to the lowest water level of carbonatedwater stored in the carbonated water tank 110. The minimum amount ofcarbonated water may be different according to the carbonated water tank110, and may be set to “0”.

When the amount of remaining carbonated water is less than the minimumamount of carbonated water (YES of operation 2470), the refrigerator 1′may start to produce carbonated water (operation 2480).

Particularly, the refrigerator 1′ may produce carbonated water bysupplying purified water and carbon dioxide gas to the carbonated watertank 110.

When the amount of remaining carbonated water is not less than theminimum amount of carbonated water (NO of operation 2470), therefrigerator 1′ may store the amount of remaining carbonated water(operation 2490).

The refrigerator 1 may store the amount of remaining carbonated water ina memory 520 of a controller 500 or a storage 400 to estimate the amountof remaining carbonated water when carbonated water is discharged.

As mentioned above, the refrigerator 1′ may detect the amount ofdischarged carbonated water by using the second flow sensor 193 providedon the integrated discharge flow path 190, and may estimate the amountof remaining carbonated water of the carbonated water tank 110 based onthe detected amount of discharged carbonated water.

FIG. 35 is a view illustrating a method of determining an abnormality ina carbonated water discharge valve of a refrigerator according toanother embodiment of the present disclosure.

A method of determining an abnormality in the carbonated water dischargevalve 2500 in which the refrigerator 1′ determines an abnormality in thecarbonated water discharge valve 135 will be described with reference toFIG. 35.

The refrigerator 1′ may determine whether carbonated water is discharged(operation 2510).

The refrigerator 1′ may determine whether carbonated water is dischargedbased on a control signal provided to the carbonated water dischargevalve 135.

Particularly, when an open valve signal is provided to the carbonatedwater discharge valve 135, the refrigerator 1′ may determine thatcarbonated water is discharged, and when a close valve signal isprovided to the carbonated water discharge valve 135, the refrigerator1′ may determine that carbonated water is not discharged.

When it is determined that carbonated water is discharged (YES ofoperation 2510), the refrigerator 1′ may detect the discharge of thecarbonated water by using the second flow sensor 193 (operation 2520).

When the carbonated water discharge valve 135 is opened, the second flowsensor 193 may detect the discharge of the carbonated water sincecarbonated water is discharged from the carbonated water tank 110 viathe carbonated water discharge valve 135 and the second flow sensor 193.

When the discharge of the carbonated water is detected (YES of operation2520), the refrigerator 1′ may determine that there is no abnormality inthe operation of the carbonated water discharge valve 135.

Conversely, the discharge of the carbonated water is not detected (NO ofoperation 2520), the refrigerator 1′ may warn the abnormality in thecarbonated water discharge valve 135 (operation 2530).

What the second flow sensor 193 does not detect the discharge of thecarbonated water may represent that the carbonated water discharge valve135 is not opened. That is, since the carbonated water discharge valve135 is not opened although the open valve signal is provided to thecarbonated water discharge valve 135, the refrigerator 1′ may determinethat there is an abnormality in the carbonated water discharge valve135.

The refrigerator 1′ may warn the abnormality in the carbonated waterdischarge valve 135 to a user via the user interface 300.

When it is determined that carbonated water is not discharged (NO ofoperation 2510), the refrigerator 1′ may detect the discharge of thecarbonated water by using the second flow sensor 193 (operation 2540).

When the carbonated water supply valve 135 is normally operated in astate where the close valve signal is provided to the carbonated waterdischarge valve 135, the discharge of the carbonated water may be notdetected.

When the discharge of the purified water is not detected (NO ofoperation 2540), the refrigerator 1′ may determine that there is noabnormality in the operation of the carbonated water discharge valve135.

When the discharge of the carbonated water is detected (YES of operation2540), the refrigerator 1′ may warn an abnormality in the carbonatedwater discharge valve 135 (operation 2550).

What the second flow sensor 193 detects the discharge of the carbonatedwater may represent that the carbonated water discharge valve 135 is notclosed.

That is, since the carbonated water discharge valve 135 is not closedalthough the close valve signal is provided to the carbonated waterdischarge valve 135, the refrigerator 1′ may determine that there is anabnormality in the carbonated water discharge valve 135.

The refrigerator 1′ may warn the abnormality in the carbonated waterdischarge valve 135 to a user via the user interface 300.

As mentioned above, the refrigerator 1′ may determine the presence ofthe abnormality in the carbonated water discharge valve 135 by using thesecond flow sensor 193.

FIG. 36 is a view illustrating a carbonated water production module anda purified water supply module of a refrigerator according to anotherembodiment of the present disclosure;

A purified water supply module 70″ and a carbonated water productionmodule 100″ included in a refrigerator 1″ according to anotherembodiment will be described with reference to FIG. 36. However, adescription of the same parts as the purified water supply module andthe carbonated water production module shown in FIG. 5 will be omitted.

As illustrated in FIG. 36, the purified water supply module 70″ mayinclude a purified water tank 71, a purification filter 73, a flow pathswitching valve 75, and a flow sensor 77, and the carbonated waterproduction module 100″ may include a carbonated water tank 110, a carbondioxide gas cylinder 120, a valve assembly 130, a variety of flow paths150, 160, 170, 180, and 190, and a module case 140.

The carbonated water tank 110 may include a water level sensor 111 tomeasure the amount of purified water or carbonated water stored in thecarbonated water tank 110, a pressure sensor 112, a carbon dioxide gasdischarge valve 113, and a safety valve 114.

The water level sensor 111 may include a first electrode 111 a and asecond electrode 111 b, both of which have the same length, and a thirdelectrode 111 c having different length from the first electrode 111 aand the second electrode 111 b.

For example, each end of the first electrode 111 a and the secondelectrode 111 b may be disposed at a height corresponding to the lowestcarbonated water level, and an end of the third electrode 111 c may bedisposed at a height corresponding to the highest carbonated waterlevel. In this case, when the current is conducted between any oneelectrode between the first electrode 111 a and the second electrode 111b, and the third electrode 111 c, the refrigerator 1″ may determine thatthe carbonated water level is higher than the highest carbonated waterlevel. Also, when the current is not conducted between the firstelectrode 111 a and the second electrode 111 b, the refrigerator 1″ maydetermine that the carbonated water level is lower than the lowestcarbonated water level.

In summary, the water level sensor 111 may include three electrodes 111a, 111 b, 111 c, and may determine whether the carbonated water level isthe highest level and whether the carbonated water level is the lowestlevel, wherein the carbonated water is stored in the carbonated watertank 110.

However, the water level sensor 111 is not limited thereto. For example,the water level sensor 111 may include two electrodes and may determinewhether the carbonated water level is the highest level or the lowestlevel. For another example, the water level sensor 111 may include fouror more electrodes and may detect more than three point of the waterlevel according to the number of electrodes.

A first purified water supply valve 160, a second purified water supplyvalve 170, a carbonated water discharge flow path 180 and an integrateddischarge flow path 190 may be provided among the carbonated water tank110, the carbon dioxide gas cylinder 120, and the valve assembly 130.

FIG. 37 is a view illustrating a method of producing carbonated water ofa refrigerator according to another embodiment of the presentdisclosure.

A method of producing carbonated water 2700 of a refrigerator 1″ will bedescribed with reference to FIG. 37

At first, the refrigerator 1″ may determine whether conditions forstarting to produce carbonated water are satisfied (operation 2710). Theterm of “conditions for starting to produce carbonated water” mayrepresent conditions to allow the refrigerator 1″ to start to producecarbonated water.

When a water level of carbonated water stored in the carbonated watertank 110 is lower than the lowest level, the refrigerator 1″ mayautomatically start to produce carbonated water. In addition, when theuser inputs a command of activating carbonated water production throughthe user interface 300, the refrigerator 1″ may start to producecarbonated water.

The refrigerator 1″ may display carbonated water production on the userinterface 300 (operation 2720). For example, the refrigerator 1″ maydisplay the carbonated water production image on a carbonated waterproducing display unit 313 (refer to FIG. 11) provided in a carbonatedwater producing activation unit 310 (refer to FIG. 11).

The refrigerator 1″ may supply purified water to the carbonated watertank 110 (operation 2730).

The refrigerator 1 may open a purified water supply valve 131 to supplypurified water to the carbonated water tank 110.

At this time, the refrigerator 1″ may open a carbon dioxide gasdischarge valve 152 to smoothly supply purified water to the carbonatedwater tank 110. Therefore, it may prevent a condition where purifiedwater is not smoothly supplied to the carbonated water tank 110 when aninternal pressure of the carbonated water tank 110 is higher than asupply pressure of purified water due to carbon dioxide gas in thecarbonated water tank 110.

The refrigerator 1″ may determine whether the water level of waterstored in the carbonated water tank 110 is higher than the highest level(operation 2740).

The refrigerator 1″ may determine whether the water level of purifiedwater stored in the carbonated water tank 110 is higher than the highestlevel by using the water level sensor 111.

When the current is conducted between any one electrode between thefirst electrode 111 a and the second electrode 111 b, both of which arelong and the third electrode 111 c which is short, the refrigerator 1″may determine that the carbonated water level is higher than the highestcarbonated water level.

When the water level of purified water is not higher than the highestlevel (NO of operation 2740), the refrigerator 1″ may continue to supplypurified water to the carbonated water tank 110.

When the water level of purified water stored in the carbonated watertank 110 is higher than the highest level (YES of operation 2740), therefrigerator 1″ may stop supplying purified water to the carbonatedwater tank 110, and may supply carbon dioxide gas to the carbonatedwater tank 110 (operation 2760).

To supply carbon dioxide gas to the carbonated water tank 110, therefrigerator 1″ may close the purified water supply valve 131 and thecarbon dioxide gas discharge valve 113, and then may open the carbondioxide gas supply valve 152 for a predetermined carbon dioxide gassupply time.

The refrigerator 1″ may wait for a carbon dioxide dissolution time todissolve carbon dioxide gas in purified water (operation 2770).

Despite of supplying carbon dioxide gas to the carbonated water tank 110where purified water is filled, carbon dioxide gas may be notimmediately dissolved. It may require from several minutes to severalten minutes to dissolve sufficient amount of carbon dioxide gas inpurified water even there may be differences according to the pressureof carbon dioxide gas, the concentration of carbon dioxide gas dissolvedin purified water, and the likes.

When the carbon dioxide gas dissolution time is expired after supplyingcarbon dioxide gas, the refrigerator 1″ may determine whether theconcentration of carbonated water stored in the carbonated water tank110 reaches a target concentration (operation 2780).

For example, to determine whether the concentration of carbonated waterstored in the carbonated water tank 110 reaches a target concentration,the refrigerator 1″ may determine whether the concentration ofcarbonated water reaches a target concentration based on a supply timeof a carbon dioxide gas supplied to the carbonated water tank 110. Thisis because carbon dioxide gas at a certain pressure is supplied to thecarbonated water tank by the carbon dioxide gas regulator 151.

For another example, the refrigerator 1″ may determine whether theconcentration of carbonated water reaches the target concentration basedon the number of supply times of carbon dioxide gas to the carbonatedwater tank 110.

The carbon dioxide gas pressure of the inside of the carbonated watertank 110 may be limited below a certain pressure, and thus therefrigerator 1″ may repeatedly supply carbon dioxide gas and dissolvecarbon dioxide gas to dissolve a large amount of carbon dioxide gas inpurified water.

In other words, the refrigerator 1″ may change the number of times ofsupplying carbon dioxide gas according to a target concentrationinputted by the user, and may change the supply time of carbon dioxidegas and the carbon dioxide gas dissolution time according to the numberof supply times.

To determine whether a carbonated water concentration reaches the targetconcentration, the refrigerator 1″ may determine whether the number ofsupply times of carbon dioxide gas supplied to the carbonated water tank110 corresponds to the number of supply times of carbon dioxide gasaccording to the target concentration.

When it is determined that the concentration of the carbonated waterdoes not reach the target concentration (NO of operation 2780), therefrigerator 1″ may repeatedly supply carbon dioxide gas and dissolvecarbon dioxide gas to the carbonated water tank 110.

When it is determined that the concentration of the carbonated waterreaches the target concentration (YES of operation 2780), therefrigerator 1″ may display the completion of the carbonated waterproduction on the user interface 300 (operation 2790).

For example, the refrigerator 1″ may display a completion of thecarbonated water production image on the carbonated water productiondisplaying unit 313 (refer to FIG. 11) included in the carbonated waterproducing activation unit 310 (refer to FIG. 11).

As mentioned above, the refrigerator 1″ may produce carbonated water atvarious concentrations by using the carbonated water production module100″.

FIG. 38 is a view illustrating an example of a method of determining anabnormality in a water level sensor of a refrigerator according toanother embodiment of the present disclosure.

A method of determining an abnormality in the water level sensor 2100 inwhich the refrigerator 1″ determines an abnormality in the water levelsensor 111 will be described with reference to FIG. 38.

The refrigerator 1″ may determine whether carbon dioxide gas is suppliedto the carbonated water tank 110 (operation 2110).

The refrigerator 1″ may determine whether carbon dioxide gas is suppliedbased on a control signal provided to the carbon dioxide gas supplyvalve 152 and the carbon dioxide gas discharge valve 113.

Particularly, when a close valve signal is provided to the carbondioxide gas discharge valve 113, and an open valve signal is provided tothe carbon dioxide gas supply valve 152, the refrigerator 1″ maydetermine that carbon dioxide gas is supplied to the carbonated watertank 110. In addition, when a close valve signal is provided to thecarbon dioxide gas supply valve 152, the refrigerator 1″ may determinethat carbon dioxide gas is not supplied.

When it is determined that carbon dioxide gas is not supplied (NO ofoperation 2110), the refrigerator 1″ may continue to perform anoperation previously performed.

When it is determined that carbon dioxide gas is supplied (YES ofoperation 2110), the refrigerator 1 may determine whether the internalpressure of the carbonated water tank 110 is higher than the referenceinternal pressure (operation 2120).

The refrigerator 1″ may detect the internal pressure of the carbonatedwater tank 110 by using the carbonated water tank pressure sensor 112,and may compare the detected internal pressure with the referenceinternal pressure.

The term of the reference internal pressure may represent an internalpressure to allow the carbonated water tank 110 to discharge carbonatedwater by using the internal pressure of the carbonated water tank 110.As mentioned above, the carbonated water tank 110 may dischargecarbonated water by using the internal pressure of the carbonated watertank 110. That is, the carbonated water tank 110 may dischargecarbonated water by using differences between the internal pressure ofthe carbonated water tank 110 and the atmospheric pressure.

In addition, the carbonated water tank 110 may discharge carbonatedwater at more than a certain pressure for the user convenience.

To discharge carbonated water at more than a certain pressure, theinternal pressure of the carbonated water tank 110 may be higher thanthe reference internal pressure, and carbon dioxide gas may be suppliedto allow the internal pressure of the carbonated water tank 110 to behigher than the reference internal pressure.

When the internal pressure of the carbonated water tank 110 is higherthan the reference internal pressure (YES of operation 2120), therefrigerator 1″ may determine that there is no abnormality in theoperation of the water level sensor 111.

When the internal pressure of the carbonated water tank 110 is nothigher than the reference internal pressure (NO of operation 2120), therefrigerator 1″ may warn the abnormality of the water level sensor 111(operation 2130).

What the internal pressure of the carbonated water tank 110 is nothigher than the reference internal pressure although carbon dioxide gasis supplied may represent that there are many empty spaces inside thecarbonated water tank 110. In addition, it may represent that the waterlevel of the purified water supplied to the carbonated water tank 110,when producing carbonated water, does not reach the highest water level.

The water level of the purified water may be detected by the water levelsensor 111, and thus the refrigerator 1″ may determine that the waterlevel of the purified water is the highest water level due to themalfunction of the water level sensor 111 although the water level ofthe purified water does not reach the highest water level.

Therefore, the refrigerator 1″ may display the abnormality in the waterlevel sensor 111 by using the user interface 300.

As mentioned above, the refrigerator 1″ may determine the presence ofthe abnormality in the water level sensor 111 by using the carbonatedwater tank pressure sensor 112.

FIG. 39 is a view illustrating another example of a method ofdetermining an abnormality in a water level sensor of a refrigeratoraccording to another embodiment of the present disclosure.

A method of determining an abnormality in the water level sensor 2200 inwhich the refrigerator 1″ determines an abnormality in the water levelsensor 111 will be described with reference to FIG. 39.

The refrigerator 1″ may determine whether conditions for starting toproduce carbonated water are satisfied (operation 2210).

The term of “conditions for starting to produce carbonated water” mayrepresent conditions to allow the refrigerator 1″ to start to producecarbonated water. For example, when a carbonated water level ofcarbonated water stored in the carbonated water tank 110 is lower thanthe lowest level, the refrigerator 1″ may automatically start to producecarbonated water. In addition, when the user inputs a command ofcarbonated water production activation through the user interface 300,the refrigerator 1″ may start to produce carbonated water.

The refrigerator 1″ may supply purified water to the carbonated watertank 110 (operation 2220).

The refrigerator 1″ may open the purified water supply valve 131 tosupply purified water to the carbonated water tank 110. In addition, therefrigerator 1″ may open the carbon dioxide gas discharge valve 152 tosmoothly supply purified water to the carbonated water tank 110.Therefore, it may prevent a condition where purified water is notsmoothly supplied to the carbonated water tank 110 when an internalpressure of the carbonated water tank 110 is higher than a supplypressure of purified water due to carbon dioxide gas in the carbonatedwater tank 110.

The refrigerator 1″ may determine whether the water level of purifiedwater stored in the carbonated water tank 110 is higher than the highestlevel (operation 2230).

The refrigerator 1″ may determine whether the water level of purifiedwater stored in the carbonated water tank 110 is higher than the highestlevel by using the water level sensor 111.

When the current is conducted between any one electrode between thefirst electrode 111 a and the second electrode 111 b, both of which arelong and the third electrode 111 c which is short, the refrigerator 1″may determine that the carbonated water level is higher than the highestwater level.

When the water level of purified water is not higher than the highestlevel (NO of operation 2230), the refrigerator 1″ may continue to supplypurified water.

When the water level of purified water is higher than the highest level(YES of operation 2230), the refrigerator 1″ may determine whether theamount of supplied purified water is less than the amount of thepurified water, which is suppliable (operation 2240).

Purified water is supplied to the carbonated water tank 110 by the waterpressure of the external water source 40, and thus the amount ofpurified water supplied to the carbonated water tank 110, may be thesame as the amount of purified water which is supplied to the purifiedwater supply module 70″ from the external water source 40. In addition,the refrigerator 1″ may estimate the amount of the purified watersupplied to the purified water supply module 70″ from the external watersource 40 by using the flow sensor 77.

Therefore, the refrigerator 1″ may detect the amount of purified watersupplied to the carbonated water tank 110 by using the flow sensor 77,and may compare the detected amount of supplied purified water with theamount of suppliable purified water.

The term of the amount of suppliable purified water may represent theamount of purified water, which is allowed to be supplied to thecarbonated water tank 110 when carbonated water is produced.

Particularly, when the production of carbonated water is started sincethe water level of carbonated water reaches the lowest water level, theamount of suppliable purified water may represent the maximum amount ofpurified water corresponding to the highest water level of thecarbonated water tank 110. In addition, when the production ofcarbonated water is started due to the user′ command of producingcarbonated water, the amount of suppliable purified water may representthe difference between the maximum amount of purified watercorresponding to the highest water level of the carbonated water tank110 and the amount of remaining carbonated water stored in thecarbonated water tank 110.

When the amount of supplied purified water is less than the amount ofsuppliable purified water (YES of operation 2240), the refrigerator 1″may warn an abnormality in the water level sensor 111 (operation 2250).

What the amount of supplied purified water is less than the amount ofsuppliable purified water may represent that the water level of purifiedwater supplied to the carbonated water tank 110 does not reach thelowest water level.

The water level of the purified water may be detected by the water levelsensor 111, and thus the refrigerator 1″ may determine that the waterlevel of the purified water is the highest water level due to themalfunction of the water level sensor 111 although the water level ofthe purified water does not reach the highest water level.

Therefore, the refrigerator 1″ may display the abnormality in the waterlevel sensor 111 by using the user interface 300.

When the amount of supplied purified water is not less than the amountof suppliable purified water (NO of operation 2240), the refrigerator 1″may supply carbon dioxide gas to the carbonated water tank 110(operation 2260).

Particularly, the refrigerator 1″ may open the carbon dioxide gas supplyvalve 152 to supply carbon dioxide gas.

As mentioned above, the refrigerator 1″ may determine the presence ofthe abnormality in the water level sensor 111 by using the flow sensor77.

Although a few embodiments of the present disclosure have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the disclosure, the scope of which is definedin the claims and their equivalents.

1. A refrigerator comprising: a carbonated water tank to storecarbonated water; a carbonated water tank pressure sensor to detect aninternal pressure of the carbonated water tank; a purified water supplyvalve to open/close a purified water supply flow path to guide waterfrom a purified water tank to the carbonated water tank; a carbondioxide gas supply valve to open/close a carbon dioxide gas supply flowpath to guide carbon dioxide gas from a carbon dioxide gas cylinder tothe carbonated water tank; and a controller to open the purified watersupply valve and the carbon dioxide gas supply valve in sequence toproduce carbonated water, wherein, when an internal pressure of thecarbonated water tank is lower than a minimum pressure after carbonatedwater is produced, the controller opens the carbon dioxide gas supplyvalve so that the internal pressure of the carbonated water tank isequal to or higher than the minimum pressure.
 2. The refrigerator ofclaim 1 further comprising: a carbon dioxide gas discharge valve tocontrol the discharge of carbon dioxide gas in the carbonated watertank, wherein, when an internal pressure of the carbonated water tank ishigher than a maximum pressure, the controller opens the carbon dioxidegas discharge valve so that the internal pressure of the carbonatedwater tank is equal to or lower than the maximum pressure.
 3. Therefrigerator of claim 1 wherein while the carbonated water is produced,the controller warns the change of the carbon dioxide gas cylinder whenthe internal pressure of carbonated water tank is lower than a referencepressure, just after the carbon dioxide gas is supplied.
 4. Therefrigerator of claim 1, further comprising a carbon dioxide gasdischarge valve to control the discharge of carbon dioxide gas in thecarbonated water tank; and wherein, while the carbonated water isproduced, the controller displays an abnormality in at least one of thecarbon dioxide gas supply valve and the carbon dioxide gas dischargevalve based on a detection result of the carbonated water tank pressuresensor.
 5. The refrigerator of claim 4 wherein the controller warns anabnormality in the carbon dioxide gas discharge valve based on a controlvalve signal that is provided to the carbon dioxide gas discharge valveand the detection result of the carbonated water tank pressure sensorwhile the carbonated water is produced.
 6. The refrigerator of claim 5wherein the controller warns an abnormality in the carbon dioxide gasdischarge valve when the internal pressure of the carbonated water tankis higher than atmospheric pressure after delivering an open valvesignal to the carbon dioxide gas discharge valve.
 7. The refrigerator ofclaim 5 wherein, the controller opens the carbon dioxide gas dischargevalve when the internal pressure of the carbonated water tank is thesame as atmospheric pressure after delivering an open valve signal tothe carbon dioxide gas discharge valve.
 8. The refrigerator of claim 4wherein the controller warns an abnormality in the carbon dioxide gassupply valve based on a control valve signal that is provided to thecarbon dioxide gas supply valve and a detection result of the carbonatedwater tank pressure sensor while the carbonated water is produced. 9.The refrigerator of claim 8 wherein the controller warns an abnormalityin the carbon dioxide gas supply valve when the internal pressure of thecarbonated water tank is not increased after delivering an open valvesignal to the carbon dioxide gas supply valve.
 10. A refrigeratorcomprising: a carbonated water tank to store carbonated water; acarbonated water tank pressure sensor to detect an internal pressure ofthe carbonated water tank; a carbonated water discharge valve toopen/close a carbonated water discharge flow path to guide carbonatedwater stored in the carbonated water tank to the outside of therefrigerator; and a controller to warn an abnormality in the carbonatedwater discharge valve based on a detection result of the carbonatedwater tank pressure sensor.
 11. The refrigerator of claim 10 wherein thecontroller warns an abnormality in the carbonated water discharge valvewhen the internal pressure of the carbonated water tank is not reducedafter delivering an open valve signal to the carbonated water dischargevalve.
 12. The refrigerator of claim 10 wherein the controller warns anabnormality in the carbonated water discharge valve when the internalpressure of the carbonated water tank is reduced after delivering aclose valve signal to the carbonated water discharge valve.
 13. Acontrol method of a refrigerator capable of producing carbonated watercomprising: supplying water and carbon dioxide gas sequentially to acarbonated water tank to produce carbonated water; detecting an internalpressure of the carbonated water tank by a carbonated water tankpressure sensor after carbonated water is produced; and resupplyingcarbon dioxide gas to the carbonated water tank when the detectedinternal pressure of the carbonated water tank is lower than a minimumpressure, so that the internal pressure of the carbonated water tank ishigher than a reference pressure.
 14. The control method of claim 13further comprising: discharging carbon dioxide gas from the carbonatedwater tank when the detected internal pressure of the carbonated watertank is higher than the maximum pressure, so that the internal pressureof the carbonated water tank is lower than a maximum pressure.
 15. Thecontrol method of claim 13 further comprising: detecting an internalpressure of the carbonated water tank by a carbonated water tankpressure sensor while carbonated water is produced, and warning of thechange of a carbon dioxide gas cylinder when the internal pressure ofthe carbonated water tank is lower than the reference pressure.
 16. Thecontrol method of claim 13, further comprising displaying an abnormalityin at least one valve of the carbon dioxide gas supply valve and thecarbon dioxide gas discharge valve based a detection result of thecarbonated water tank pressure sensor.
 17. The control method of claim16 wherein the displaying an abnormality in at least one valve compriseswarning an abnormality in the carbon dioxide gas discharge valve whenthe internal pressure of the carbonated water tank is higher thanatmospheric pressure after delivering an open valve signal to the carbondioxide gas discharge valve.
 18. The control method of claim 16 whereinthe displaying an abnormality in at least one valve comprises warning anabnormality in the carbon dioxide gas supply valve when the internalpressure of the carbonated water tank is not increased after deliveringa close valve signal to the carbon dioxide gas discharge valve.